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Composition of watercolors. "Watercolor paints

Full squad It is not customary to specify watercolors from manufacturers. Most often on the packaging we will find only an indication of the pigments on the basis of which the paint is made. But let's see what else can be hidden inside the tube and what role the various ingredients play.
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Everything that we will consider in this article is just general information, on the basis of which you can get an idea about the formulation of paints.
In reality, the formulation of each paint of each manufacturer is unique and is a trade secret.
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So let's get started!
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Coloring agent

The basis of any coloring composition is a coloring agent. It is he who determines the color of the future paint, its coloring ability, light fastness and many other properties. Coloring agents can be divided into pigments and dyes.
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A dye is a substance that is capable of coloring other materials, usually soluble in water.
Pigment is a colored substance that is insoluble in water. Simply put, it is a colored powder (ground very finely), the particles of which are in no way connected with each other.
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If we are talking about professional watercolors, then in most cases we are dealing with pigments.
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Not only are the pigment particles themselves in no way connected to each other, they also do not form any connection with the surface on which they are applied. If we tried to paint with a mixture of pigment and water, after drying, this mixture would begin to crumble from the sheet.

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In order to ensure that the pigment particles adhere to the surface and that the ink interacts with the paper in the way we are used to, a so-called binder is used.
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Also, it is the binder that determines the type of future paint. Of course, we are talking about watercolor, where a water-soluble binder is used. But, if instead of it we take, for example, linseed oil, then we could get oil paints. After all, the pigments, for the most part, are the same in paints.
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The main advantage of a watercolor binder is that it can be re-dissolved in water even after it has completely dried. That is why watercolor paints that have dried on the palette are enough to moisten with water for reuse, which is why we can wipe and select paint from the sheet even after the paint layer has dried.

What can serve as a binder for watercolor?

Historically, people have used a whole variety of different substances - these could be resins, starches, animal adhesives, and so on.
That is, there was no single option. By the way, according to one theory, this is why watercolor got its name not in honor of the binder (like oil or acrylic), but in honor of its solvent - water.
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In the 18th century, gum arabic began to be used in Europe, and it remains the most popular watercolor binder to this day. Gum arabic is a hard, transparent resin of a yellowish hue, consisting of the dried juice of some types of acacia.
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The price of gum arabic is quite high, so cheaper binders are used in budget series and general purpose paints. For example, dextrin is actively used - a substance obtained from various starches. Also, as a replacement, there are worthy options not only for vegetable, but also for synthetic binders.

Additives and fillers

The first commercial watercolors consisted mainly of pigment, water and gum arabic and were solid tiles. Before use, such tiles had to be grated and soaked in water for a long time.
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In order for our paint to have the usual pasty consistency, and when dried, it is soaked from the touch with a wet brush, various plasticizers and moisturizers are added to it.
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One of the most popular plasticizers in watercolor is glycerin, and sugar syrup or honey can be used as a moisturizer.
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And those are just the basics! In addition, watercolors may also contain various dispersants, preservatives, thickeners, and so on. It is important to understand that all this is in the composition for a reason.
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Each pigment has its own characteristics, and in order to make paints from them that are approximately similar in consistency and behavior, an individual approach and unique recipes are required.

It should also be added that special fillers can be used to lower the pigment concentration and reduce the final cost of the paint. Such fillers are often used in paints based on the most expensive pigments. It is also normal practice to use them in student series, this makes paints more accessible. The addition of such fillers usually does not affect the preservation properties of the paint. However, their excessive use can lead to the so-called soapiness of the paint and reduce its saturation.
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Additives and fillers play an important role in the composition of the paint and in most cases work in favor of the consumer, unless the manufacturer abuses their quantity in pursuit of cheaper production.
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On this our brief digression came to an end. Now you know for sure that watercolor paint is not just an indefinite substance of some color, but a complex substance, each element of which fulfills its purpose.

The article was prepared by the experts of the watercolor laboratory watercolor.lab.

Today I want to talk about what beginners to paint with watercolor usually do not pay attention to, but in vain. The conversation will focus on the composition and properties of watercolors.

The books that fell into my hands when I took my first steps in watercolor simply did not have this information. It was not in the lessons with which I started. Such information is not often found in articles. But without knowing and not understanding these things, it is quite difficult to achieve those effects that so delight and fascinate in watercolor.

Therefore, having studied and analyzed this topic, I decided to write the most basic, in my opinion, here.

Basic properties of watercolor

Some general information.

1. Lightfastness

Domestic paints are divided into three groups of light fastness (when stored in museum conditions):

+++ or *** : 100 years
++ or ** : 25-100 years
+ or * : 10-25 years
o: 0-10 years

Similar markings are also available from foreign manufacturers.

2. Transparency

Watercolor paints can be opaque, translucent and transparent. The transparency of the paint is usually indicated by a square with varying degrees of shading.

3. Quantity and quality of pigments

The names of pigments are usually indicated on the label in which the cuvette is wrapped, or on a tube of watercolor paint. However, it happens that this information is not in the watercolor set, there is only the name of the color and the number. In this case, it makes sense to look for information about pigments on the manufacturer's website. I will talk more about pigments below.

How to choose watercolor paints?

In order not to get confused in the abundance of colors and not make a mistake with the choice, you need to follow the following tips:

1. Choose a professional watercolor.

Of course, student paints can also be used, but it should be remembered that they use cheaper pigments, pigment imitations (marked Hue), the color is achieved by mixing several pigments and therefore, when creating mixtures of these paints, it is more likely to get dirt instead of a pure color.

At first, I bought AquaFine student paints, in a set of 18 colors in cuvettes and 2 tubes (white and black). The pigments in the set were not listed, but there was a tab with all the names of the colors in the order they were placed in the set. Of the 18 colors in 6 Hue marks, that is, color imitation, there are only 6 single-pigment colors in the set.

Later, when I started to deal with all my watercolors, paint and study the composition and pigments, I found a manufacturer's document on the Internet, where I found out the quantity and quality of the pigments included in my set, which helped me to highlight the colors from this set, which can be used and which should not.

In general, my student set quickly became small, so I decided to buy a set of the Neva palette of 36 colors (white nights), and then gradually bought all the colors available from this brand in separate cuvettes.

As a result, I ended up with all 57 colors of the professional NP series, from which I assembled my basic palette, more precisely, even 2 palettes (large and small).

There are many labels similar to candy wrappers, which contain information on the main properties of each of the paints. Fortunately, then I already knew that in no case should they be thrown away and it would not be bad to make color cards out of them so as not to get confused in the names of colors, remember their location in the palette, and navigate the properties of the available colors. Which is exactly what I did.

On this moment I slightly reformatted my palettes, removed some colors from the basic sets, made a large coloring for all colors indicating the main properties of the colors, as well as a new coloring for colors, taking into account the new location.

And also, I realized what colors from other manufacturers I lack for complete happiness, but I will talk about this separately in an article devoted to the formation of my personal basic palette.

For now, I will limit myself to the fact that the cobalt blue, ceruleum and natural umber of the White Nights are not very good, I will replace them.

That is, when deciding to buy a watercolor, you can go in 2 ways:

1) Buy a set of 24 (36) colors (you can start with 12) White Nights. And then format it: throw something away, buy something in addition.

2) Analyze the composition of all BN paints and select those cuvettes in the set that are completely satisfied in quality, buy the rest of the colors you need from other manufacturers, also initially analyzing their properties, reviews, price (which, by the way, is also important).

Which way to choose - everyone decides for himself. The 1st one is simpler until you realize that the set will have to be edited :). The 2nd one is more difficult, but with this approach, you will know your paints in person even before buying, however, there is another problem here, it is not always possible to rely on other people's paints and markings, there may be mistakes and disappointments.

2. Give preference to single-pigment watercolors.

Of course, this is not a hard and fast rule, you can quite successfully paint with 2- and 3-pigment paints, but you should always remember that in mixtures they need to be used very carefully, and only when you really need a complex color.

Let me take as an example a small part of the white nights palette, there are both single-pigment and multi-pigment paints and even 2 colors with absolutely identical properties (red ocher and Shahnazar red).

Abbreviations of colors in the name of pigments indicate:

W - wight (white), Y - yellow (yellow), O - orange (orange), R - red (red), V - violet (violet), B - blue (blue), G - green (green), Br - brown (brown), Bk - black (black).

Why do you need to know all this? The fact is that the numbering and name of the color for each manufacturer may differ (and differ), but the names of the pigments used in the composition of the paint have a single look and the ability to read them makes life very easy when choosing a color. In addition, it is immediately clear whether it is a pure color or a composite one. And if composite, then what does it include.

There are colors in the palette that can be easily obtained by mixing the single-pigment ones included in their composition, of course, if you know what these pigments are and what colors they correspond to.

For example, yellow-green (P.G.7, P.Y.3) is easily obtained by mixing emerald (P.G.7) and lemon (P.Y.3).

This could also be found out by trial, but it is much faster and easier to look at the composition and properties of the selected color.

3. Take into account the transparency of the paint.

The transparency of the paint is easy to recognize by the square on the label. But don't limit yourself to this knowledge. Be sure to make a painting of each color available in the palette and test how the colors behave when applied to each other. Usually, the glazing lattice exercise is used for this.

Here, for example, 3 yellow colors from white nights:

Lemon - P.Y.3,
Lemon cadmium - P.Y.35,
Cadmium yellow medium - P.Y.35.

I specifically chose these 3 single pigment colors to demonstrate that different colors can be formed by the same pigment. In this case, cadmium lemon and cadmium yellow medium are distinguished by transparency (look at how the square is filled). That is, colors from the same pigment will have different properties in mixtures, look different on color stretches and in glazes. This important point, which you need to know and consider when painting with watercolor.

Cuvettes or tubes

In general, I only have 6 tubes from the same Aquafine student series as the first set. I bought these tubes for testing, and, to be honest, I have not yet appreciated the convenience. True, I don’t draw in large formats, I don’t do large fills, when you really can’t do without tubes.

In my case, cuvettes are quite enough, although I do not exclude that over time I will come to tubes. However, the same Neva palette has tubes for only 12 colors. So you will have to study other manufacturers in more detail.

That's all about watercolor paints for now 🙂

MBOU Ostankino secondary school

Research

Nomination: chemistry and biology

"Watercolor paints. Their composition and production

Work done:

Lyozova Anna, Lyutyanskaya Maria

Head: Bolshova M.V.

Chemistry and biology teacher

2016

1. Plan ……………………………………………………... page 3.

2. Introduction ………………………………………………… p. 4-6.

3. The main part …………………………………………….. pp. 7-27.

4. Conclusion ………………………………………………. pp. 28-30.

5. Literature ……………………………………………… page 31.

Plan

I. Introduction.

1. Relevance of the topic.

2. Purpose.

3. Tasks.

4. Research methodology.

II. Main part. Watercolor paints. What do we know about them?

1. Theoretical part:

3. The process of preparing paints.

4. Features of watercolors.

2.Practical part.

III. Conclusion.

IV. Literature.

I. Introduction.

Colors play a huge role in our life. At the same time, most often we don’t even notice them - our clothes, toys, kitchen appliances, the walls of our house are painted, various landscapes skillfully made with watercolors can hang on the walls. Who doesn't know watercolor? Box with colorful tiles, round jars. The cheerful blue of the sky, the lace of the clouds, the veil of fogs are best conveyed in watercolor. And how useful it is when you need to depict a sunset, running waves, thickening twilight, fabulous flowers, an underwater kingdom, a cosmic landscape!Watercolor paints are distinguished by transparency, tenderness, juiciness. But they can also be very bright, deep.

We consider the theme of our workrelevant , since in our country the establishment of the production of household chemicals (including the manufacture of paints), as the most important sub-sector of the chemical industry, began relatively recently (1968).

In our free time, we like to draw with paints, so this work is especially interesting for us. And perhaps the skills and knowledge we gained in the course of this work will be useful in the future and help in choosing a profession. Or maybe they will allow in the future to create new varieties of paints.

Our drawings

Target : making watercolors from natural ingredients at home.

Tasks : 1. Study the composition and properties of watercolors.

2. Find out the functional significance of the paint components.

3. Consider the main stages of paint production.

4. Prepare the basis of watercolor paints from vegetable raw materials and obtain vegetable pigments.

Hypothesis : Working only with plant material, it is possible to obtain watercolors based on natural pigments even at home.

Research methods :

Study and analysis of scientific and popular science literature, Internet resources on the research problem.

Experiment: physical and chemical methods for obtaining plant pigments and paints based on them.

Processing and analysis of experimental data.

The work is devoted to the study of the physical and chemical properties of watercolors. In the theoretical part, the properties and features of watercolor paints are considered. The characteristic of the main components of paints is given. The issue of industrial production of watercolors is touched upon.

In the practical part of the work, a description is given of methods for obtaining paints at home. A technique for obtaining a base for watercolors based on available raw materials is given.

Main part.

1. The history of paint - from the cave to the modern facade.

The history of colors began with the advent of man. The cave dwellers painted on the stones what surrounded them: running animals and hunters with spears. The richer and more complex life became, the more colors were required to capture it. Currentlywithout colors, our world would be gray, so man has always sought to find a way to decorate reality. Now paints are made from both natural and synthetic materials.

The appearance of paints and drawing dates back to prehistoric times. Paints were known long before there were written reports about them. The colorful images on the walls of the cave dwellings have been preserved to this day in relatively good condition. Some of them existed as far back as 15,000 BC. Thus, we can assume that the appearance of colorful substances was one of the first discoveries at the dawn of civilization.

Dark shades of paint were obtained by adding black to ocher. charcoal. Primitive artists kneaded their paints with animal fat to better adhere to the stone. The resulting color for a long time remained sticky and wet, as animal fats do not dry as easily in the air to form a hard film, like modern paints. The bodies of the dead were covered with red ocher, similar in color to blood, before burial.

used to paint it was impossible to store for more than one day, as they oxidized and hardened upon contact with air. It was difficult to work with these paints: darker paints with a high charcoal content dried much more slowly than shades with a high ocher content.

In the Renaissance, each master had his own recipe for diluting paints: some kneaded pigment on egg white - this was done by the Italians Fra Angelico and Piero Della Francesca. Others preferred casein (a milk protein already used for frescoes in Roman temples). And the Fleming Jan van Eyck introduced oil paints. He learned to apply them in thin layers. This technique best conveyed space, volume and color depth.

Some paints have long remained fabulously expensive. Ultramarine blue paint was obtained from lapis, which was brought from Iran and Afghanistan. This mineral was so expensive that the artists used ultramarine only in exceptional cases, if the customer agreed to pay for the paint in advance.

Artificial paints were significantly cheaper than natural ones, but there was one important "but": they could cause allergies, and often worsen health.

In 1870, the international society of dyers decided to find out which dyes were harmful to health. It turned out that "none", except for one: emerald green. It was made from a mixture of vinegar, copper oxide and arsenic. This paint was used to paint the walls in Napoleon's house on Saint Helena. Many researchers believe that he died from poisoning with arsenic fumes that came from the wallpaper.

50 years ago, the composition of the paint mainly included: a pigment or a mixture of pigments, linseed oil in one of the many forms that existed then (linseed oil, polymerized linseed oil) and turpentine as a thinner. The thinner was necessary in order to bring the paint to the desired consistency. At that time, ready-to-use paints had a similar composition.

Since then, however, much has changed in the composition of the paint, and paints have appeared that have greater strength and best qualities for easy brush application, no brush marks and good flow. Turpentine has been largely replaced by other solvents. As for pigments, most of those used 50 years ago are still in use today: natural earth pigments. varying degrees purity and artificially prepared white lead. Over time, this assortment has been replenished with new products from the chemical industry, organic and inorganic.

Previously, there were more poisonous paints: arsenic was included in cinnabar ("yellow gold"), and lead - in red-orange minium. Today, the palette of artificial colors is very wide. More pigments are produced artificially and are of inorganic origin - they are more stable, have a constant high-quality chemical composition, which is very important in mass production. The demand for paints is growing - this is due to the improvement of production techniques and the transition to more environmentally friendly technologies.

The history of the development of watercolor painting.

The term watercolor has several meanings.

Firstly, it means painting with special water-soluble paints. And in this case, it is customary to talk about the watercolor technique (i.e., a certain process of creativity in the visual arts).

Secondly, it is used to directly refer to the water-soluble (watercolor) paints themselves. When dissolved in water, they form a transparent aqueous suspension of fine pigment, which is the basis of the paint, thanks to which it is possible to create a unique effect of lightness, airiness and subtle color transitions.

Third , so it is customary to call the works themselves, made in this technique with watercolors. Their distinctive features are mainly in the transparency of the thinnest paint layer remaining on the paper after the water dries. In this case, white is not used, since their role is played by the white color of the paper, translucent through paint layer or not colored at all.

Watercolor has been known since ancient times. Its history begins in China after the invention of paper in the 2nd century AD. In XIIIn the 13th century, paper became widespread in Europe, primarily in Spain and Italy. The forerunner of the watercolor technique in Europe was painting on wet plaster (fresco), which made it possible to obtain similar effects.

In Europe, watercolor painting came into use later than other types of painting. Some artists mentioned it only in passing as an art that did not deserve serious attention. The watercolor technique was originally applied to the coloring of architectural and topographic plans, where Chinese ink was initially used, and then other water-based paints.

Initially oil painting mainly met in albums "for memory" and souvenirs, then entered the albums of artists and appeared in art galleries and at art exhibitions.

In Russia of the last century, there were many outstanding watercolorists.

Among them - S. V. Gerasimov (1885-1964). His landscapes are magnificent: forests and rivers, gray clouds heavy with moisture, hills and valleys illuminated by the sun. He also wrote all sorts of everyday scenes. The painter told novice watercolorists: “The life around us gives an infinite number of topics for the artist. Endless fields of golden wheat, green meadows, haymaking, children’s travels around their native land - it’s interesting to depict all this on paper! And what a wealth of colors in nature! such unusual colors as you see, for example, at sunset.

Masterfully mastered watercolor painting famous artist

A. V. Fonvizin (1882-1973). He wrote gracefully, lightly, boldly, juicy on wet paper.

A. A. Ivanov he wrote simply and easily, combining a lively, impeccable drawing with pure rich colors.

P. A. Fedotov, I. N. Kramskoy, N. A. Yaroshenko, V. D. Polenov, I. E. Repin, V. A. Serov, M. A. Vrubel, V. I. Surikov... Each of them made a rich contribution to the Russian watercolor school. Soviet painters, continuing the traditions of this school, gave watercolors a new development. ThisA. P. Ostroumova-Lebedeva, P. P. Konchalovsky, S. V. Gerasimov, A. A. Deineka, A. V. Fonvizin and many others.

In 1839, Russian artists Ivanov, Richter, Nikitin, Efimov, Pimenov made an album watercolor drawings presented to Emperor Alexander II during his visit to Rome.

2. Characteristics of watercolors in terms of chemical composition, properties and basic methods of their preparation.

From time immemorial, the artist in his practice was forced to apply the knowledge of certain laws of chemistry and physics, no matter how strange it may seem at first glance.

Paints are mixtures of chemicals that were previously prepared by the artists themselves. Each master knew the secrets of grinding pigments and could have his own original recipes for obtaining paints of a certain color and quality. A modern artist no longer needs to study old or invent new recipes, but in practice, when receiving ready-made paints from the manufacturer, he still must take into account some chemical and physical characteristics of pigments and paints prepared from them. Firstan important condition is the quality of paints, which depends on the manufacturer. Second - the artist's understanding of the structure of colors. Unusually fine grinding of the pigment, which is a criterion for the quality of watercolor paint, cannot be achieved in some cases due to the nature of the chemical nature of some substances. Any paint consists of a coloring pigment and a binder:

Pigment - dry dye Binder

Coal Water

Clay Clay

Earth Oil

Malachite Egg

Lapis Lazuli Honey

Chalk Wax

Ancient artists looked for material for paints right under their feet. From red and yellow clay, by finely grinding it, you can get a red and yellow dye, or, as the artists say, a pigment. Pigment black gives coal, white - chalk, azure - blue, green gives malachite and lapis lazuli.

Metal oxides also give a green pigment. Violet dyes can be made from peach pits or grape skins.

Nowadays, almost all paints are made in laboratories and factories from chemicals. Therefore, some paints are even poisonous, for example: red cinnabar from mercury.

Dry dye cannot stick to the canvas, so you need a binder that glues dry dye particles into a single color paint - a mass. Artists took what was at hand: oil, honey, egg, glue, wax. How closer friend to the other particles of pigment, the thicker the paint. The density of the paint can be determined by looking at how a drop of honey, an egg, spreads on a long-drying drop of oil, which does not even combine with water, and leaves a greasy mark when it dries.

Different binders give different paints with different names.

Watercolor light, translucent paint requires dilution with water. The name itself says it.

Oil is part of oil paints, they are the most durable and fall on paper with bold strokes. They are stored in tubes and diluted with a solvent, kerosene or turpentine.

One of the ancient painting techniques- tempera. These are egg paints, sometimes called "egg paints".

According to their chemical composition, watercolor paints belong to the adhesive group of paints. They are ideal for those who are just starting to master the art of painting, as well as for those artists who have special requirements for the quality of the canvas.

Nowadays, several types of watercolors are produced:

1) solid paints that look like tiles various shapes,

2) soft paints enclosed in faience cups,

3) honey paints, sold, like tempera and oil paints, in pewter tubes,

4) gouache - liquid paints enclosed in glass jars.

The binder of all the best types of watercolors ismucilage : gum arabic, dextrin, tragacanth and fruit glue (cherry); in addition, honey, glycerin, candy sugar, wax and some resins, mainly balm resins. The purpose of the latter is to give the paints the ability not to be washed away so easily upon drying, which is certainly needed by those that contain too much honey, glycerin, etc. in their composition.

gum arabic - a viscous transparent liquid secreted by some types of acacias. Belongs to a group of plant substances that are highly soluble in water. According to its composition, gum arabic is not a chemically pure substance. It is a mixture of complex organic compounds, consisting mostly of glucosidic-humic acids. It is used in the manufacture of watercolors as an adhesive. After drying, it forms a transparent, brittle film, not prone to cracking and not hygroscopic.

larch glue made from larch wood.

Dextrin - powder of light yellow or white color, prepared from starch.

cherry glue collected from cherry and plum trees, has a brown color, slightly soluble in water (only fresh). Under the action of acids, it is neutralized and passes into a solution used for the preparation of watercolors.

Albumen refers to protein substances, obtained from egg white, purified from yolk and fiber, dried at 50 ° C.

Honey - a mixture of equal amounts of fructose and glucose with an admixture of water (16-18%), wax and a small amount of protein substances.

Syrup - a product obtained by hydrolysis of starch (mainly potato and maize) with dilute acids, followed by filtration and boiling of the syrup to the desired consistency. It creates a strong film on the picture and protects the paint from drying out quickly.

Glycerol - a thick syrupy liquid, miscible with water in any ratio. Glycerin belongs to the group of trihydric alcohols. It is highly hygroscopic and is introduced into the binder of watercolors to keep them in a semi-dry state and to form an elastic film.

Also, the composition of watercolors includes a plasticizer, which makes the paints soft and plastic. The plasticizers are invert sugar and glycerin. The latter does not allow to dry out, become brittle, retains moisture in paints. It is introduced into the composition of watercolors and ox bile.To protect paints from decay by mold, they contain an antiseptic, usually phenol.

Pigments in chemistry - colored chemical compounds used in the form of fine powders for dyeing plastics, rubber, chemical fibers, and the manufacture of paints. They are divided into organic and inorganic.

To give paint a particular color, the following pigments are most widely used: cinnabar, Indian yellow, yellow ocher, gummigut, red ocher, Indian ocher, cobalt, ultramarine, indigo, Prussian blue and many, many others.

The quality of paints largely depends on the pigments. Some pigments are subject to discoloration from sunlight, so the picture painted with such paints fades. The picture painted with Prussian blue fades from the action of the sun's rays, but, being brought into a dark room for a while, takes on its former appearance.

A very good material is natural mineral ocher of various colors, zinc crowns and white, brown, red and other mars.
A distinctive feature of watercolor paints is their transparency, brightness of color, purity. These properties are achieved both by the purity of the materials used and by the large dispersion of pigments, for which special grinding of powders is used.

When, when you need dullness, opacity, use a mixture of watercolor and gouache paints. For the same purpose, paints are diluted in soapy water.

3. The process of making paints

None of the methods of painting needs such finely divided paints as watercolor; which is why making good watercolors by hand is not an easy task. But, in addition to fine grinding of paints, when making watercolors, another, no less important condition must be observed - the paints must be composed in such a way that their powder, when the watercolor is most abundantly diluted with water, “hangs” in the binder and does not fall out of it.

First they look for raw materials. It can be coal, chalk, clay, lapis lazuli, malachite. Raw materials must be cleaned of foreign impurities. The materials must then be ground to a powder.

Coal, chalk and clay can be ground at home, but malachite and lapis lazuli are very hard stones, special tools are needed to grind them. Ancient artists ground the powder in a mortar with a pestle. The resulting powder is the pigment.

Then the pigment must be mixed with a binder. As a binder, you can use: egg, oil, water, glue, honey. The paint must be mixed well so that there are no lumps. The resulting paint can be used for painting.

4. Features of watercolor paints

watercolor painting transparent, clean and bright in tone, which is difficult to achieve through glazing with oil paints. In watercolor, it is easier to achieve the subtlest shades and transitions. Watercolor paints are also used in underpainting for oil painting.

The hue of watercolors changes when it dries - brightens. This change comes from the evaporation of water, in connection with this, the gaps between the pigment particles in the paint are filled with air, the paints reflect light much more. The difference in the refractive indices of air and water causes a change in the color of the dried and fresh paint.

Strong dilution of paints with water when thinly applied to paper reduces the amount of binder, and the paint loses its tone and becomes less durable. When applying several layers of watercolor in one place, a supersaturation of the binder is obtained, and stains appear.

When covering watercolor paintings, it is very important that all paints are more or less evenly and in sufficient quantities saturated with a binder.

2. Practical part.

In old books, the names of exotic dyes are often found: red sandalwood, quercitron, carmine, sepia, logwood ... Some of these dyes are still used today, but in very small quantities, mainly for cooking artistic paints. After all, natural dyes with such beautiful names are obtained from plants and animals, and this is expensive and difficult. But natural dyes are very bright, durable, lightfast.

You can try to prepare paints using mineral substances - pigments, which may be in the school laboratory or at home.

Our experiments.

To conduct experiments, we had to get natural pigments and binders. We had at our disposal clay, coal, chalk, onion peel, potassium permanganate, PVA glue, honey and egg. We have carried out 5 experiments.

Experience 1.

1) Purify the coal from impurities.

Grind coal into powder.

Sift the powder.

Mix coal with water.

Experience 2.

1) Clean the clay from impurities.

2) Grind clay into powder.

3) Sift the powder.

4) Mix clay with glue.

Experience 3.

1) Clean the chalk from impurities.

2) Grind the chalk into powder.

3) Sift the powder.

4) Mix chalk with egg white.

Experience 4.

1) Make a thick decoction of onion peel.

2) Cool the broth.

3) Mix the decoction with honey.

Experience 5.

1) Grind potassium permanganate into a fine powder.

2) Sift the powder.

3) Mix potassium permanganate with water.

All experiments were successful, we received black, brown, white, purple, yellow paints.

Our paints turned out to be not solid, which are sold in stores. However, artists use semi-liquid watercolors in tubes of similar consistency.

After experimenting, we wanted to try other raw materials, as well as paint our drawings with new colors.

Experimental results

Now we know what watercolor paints are made of. You can prepare some paints at home. The resulting paints differ in consistency and quality from store-bought ones.

So, charcoal with water gave the paint a metallic hue, it was easily picked up on a brush and left a bright mark on the paper, quickly drying up.

Clay with glue gave a dirty brown paint, did not mix well with glue, left a greasy mark on paper and dried for a long time.

Chalk with egg white white paint, which was easily typed on a brush, left a thick mark on paper, dried for a long time, but turned out to be the most durable.

A decoction of onion peel with honey gave a yellow paint, it was well drawn on a brush, left an intense mark on paper and dried quickly.

Potassium permanganate with water formed a light brown paint, it was easily picked up on a brush and left a pale mark on paper, quickly drying.

The resulting paints have advantages and disadvantages: environmentally friendly, free, have a natural color, but labor-intensive in production, it is inconvenient to store them, and there are no saturated colors among the resulting solutions.

III. Conclusion.

Watercolor is one of the most poetic types. A lyrical, full of bright and clear images, a literary sketch or a short story is often called a watercolor. A musical composition is also compared with it, charming with gentle, transparent melodies. Watercolor can convey the serene blue of the sky, the lace of clouds, the veil of fog. It allows you to capture short-term natural phenomena. But she also has access to capital, graphic and pictorial, chamber and monumental works, landscapes and still lifes, portraits and complex compositions.

A sheet of white grainy paper, a box of paints, a soft, obedient brush, water in a small vessel - that's all the "household" of a watercolorist. Plus to this - a keen eye, a firm hand, knowledge of materials and possession of the technique of this type of painting.

Conclusions, which we made from work:

1. The history of colors began with the advent of man. They were known long before there were written reports about them.

The history of watercolors began in the 2nd century AD from China. Watercolor became fully established in European countries relatively recently - at the end of the 17th - beginning of the 18th centuries. Initially, this painting was mainly found in memory albums and souvenirs, then it entered the albums of artists and appeared in art galleries and art exhibitions.

2. The technique of watercolor painting is very diverse both in its techniques and in the way the paints are used. It differs from other techniques in its consistency, its result. Painted in watercolor in different ways. Some painters prefer to work gradually - one layer of paint is placed on another, dried up. Then the details are carefully handed over. Many take the paint at full strength and write in one layer. It is difficult to accurately show both the shape and color of objects at once.

The success of work with watercolor is very high and it is advantageous in many respects because of its properties. Watercolor is the only type of paint that is distinguished by its special transparency, purity and brightness of color.

3. Paints consist of a pigment and a binder.

Namely, watercolor paints - from dry dye and glue. They may also contain a certain amount of gum, sugar, and when used, they are rubbed with water on saucers, or directly (honey paints) are taken with a brush moistened with water from tiles or cups.

4. In the course of experiments at home, we managed to obtain watercolor paints of different colors and shades, compare their quality with store-bought paints, and analyze the advantages and disadvantages.

5. If watercolor has a future? We can confidently answer this question. Watercolor has a future! This answer can be explained by the fact that in the course of the work, its positive and problematic aspects were revealed about watercolor.

Russian painter S.V. Gerasimov said to novice watercolorists: "The life around us provides an infinite number of topics for the artist. Endless fields of golden wheat, green meadows, haymaking, children's travels around their native land - it's interesting to depict all this on paper! And what a wealth of colors in nature! No fantasy can come up with such unusual colors as you see, for example, at sunset ".

World without watercolor artistic painting will be boring and monotonous!

IV. Literature.

Alekseev V.V. - What is art? – M.: Soviet artist, 2003.

Brodskaya N.V. - Impressionism. Opening of light and color.–M.: Aurora, 2009

Cyril and Methodius. Electronic encyclopedia. Article "Watercolor" from the "Encyclopedic Dictionary of Brockhaus and Efron" (1890-1907).

http://www.akvarel.ru

http://www.lformula.ru

http://www.peredvizhnik.ru

Watercolor(derived from the Latin word aqua - water) - adhesive water-soluble paints. Painting made with these paints is also called watercolor.

Features of watercolor

Transparency. It's exclusive important feature these colors. Ways to apply watercolor and excellent results are entirely based on transparency. The reason for everything is the smallest pigment particles, which cannot be seen with the naked eye. This is achieved by the finest grinding of coloring pigments and their even distribution over the surface. The distance between the particles must be sufficient to transmit light to the surface and reflected light. White paper, translucent through a layer of paint, gives the painting an incredible luminosity and brilliance. The quality of watercolor depends on the quality of its components and proportions.

Color palette. The derivative properties of watercolor include changing shades by applying dried layers of paint on top of previous ones. With the outward simplicity of what has been said, it is not at all easy to manage color using layers. The master must have a good idea of the result - after all, there will be no opportunity to correct the picture. In watercolor, it is difficult to get by with three primary colors. Therefore, the release of watercolors is always "multi-color" (from 16 colors or more). With mechanical mixing of colors, the properties of watercolors are significantly lost, transparency and purity are reduced. However, it is the transparency of watercolor that allows you to expand color palette these colors to unprecedented sizes.

Hue, saturation. By superimposing layers of the same color on top of each other, color saturation is also achieved. Unlike gouache, watercolor is not intended to be applied pasty, as the whole meaning is lost. The properties of watercolor dictate rules to us, the main of which is the use of a large amount of water, because even the name of watercolor comes from the word "water".

Of the negative features of watercolor, one can single out low light fastness - the painting is destroyed under the influence of light, simply speaking, it fades. In addition, due to the large amount of water, the ink film is rather fragile and can be easily destroyed by external physical influences. Ensuring the long-term preservation of such paintings is not a trivial task.

Watercolor composition

pigments (fine powders),
binder - gum arabic, dextrin, cherry or sloe gum,
plasticizer (glycerin or invert sugar),
surfactant - ox bile - allows you to easily spread the paint on paper, prevents the paint from rolling into drops,
antiseptic - phenol, protects the paint from mold.

Types of watercolor

Artistic watercolor (for paintings)
Design watercolor

Honey cheap paints are widely distributed in stores for schoolchildren. And it is really possible to start acquaintance with watercolor with such paints. After, having felt the watercolor, you can switch to professional formulations. In addition, cheap paints can be used in art and sketches, where the quality of the material does not play such an important role, unlike painting.

Watercolor containers are always small, unlike gouache, since, again, they require more water when used, while gouache can be used without water if the paints are fresh.

They produce watercolor in tubes (semi-liquid watercolor), in plastic tubes (soft watercolor).

For watercolor, special paper is also applicable. Such sheets do not allow the paint to "roll", spreading evenly over the surface, and do not allow "fall through", holding the paint film on the surface. In addition, the density of the paper allows you to keep the shape with a large amount of water. As you know, when wetting and drying sheets of paper are subject to deformation.

Work with watercolors is most often carried out with brushes from the hair of squirrels of large numbers (brushes from number 4), but the refinement of details is done with brushes of lower numbers. A prerequisite for a brush when working with watercolor is the ability to hold a large supply of moisture and have a thin tear-shaped tip. Skilled master artists can produce quality work by one fifth or even seventh number, down to the smallest details.

Store in a dry, well-ventilated room at a temperature not lower than 0 degrees and not higher than 30 degrees, otherwise the quality deteriorates significantly and cannot be restored.

Chapter 13

Watercolor paints are prepared with water-soluble binders, mainly vegetable adhesives, which is why they are called water-based paints.

Watercolor was known in ancient times, but until the 17th century it had no independent meaning, it was used for coloring drawings, rough sketches, etc.

Watercolor acquired independent significance in painting starting from the 17th century. Paintings executed in watercolor are completely finished works. visual arts with a fairly well-developed manner and technique of writing. Of the Russian watercolorists, Bryullov K., Sokolov, Benois, Vrubel, Savinsky and others are known.

Paints for watercolor painting should have the following qualities.

Color according to the established standard.

Great transparency, because the whole beauty of the colorful tone when applied in a thin layer lies in this property, which is achieved by especially fine grinding of dry pigments. Good to take with a damp brush and easy to blur. The ink layer should be easily washed off with water from the surface of the paper or primer.

watercolor paint, diluted with water, should lie flat on the paper and not form spots and dots.

When exposed to direct sunlight, the paint must be lightfast and not change color.

After drying, give a durable, non-cracking layer. Do not penetrate reverse side paper. Binders for watercolors should be of high quality: after drying, they can be easily dissolved in water, have enough a high degree viscosity and adhesiveness, upon drying to give a hard, non-cracking and non-hygroscopic film.

Gum resins (gums), gum arabic, cherry, plum, apricot and other vegetable glue of stone fruit trees, as well as dextrin, honey, sugar, molasses, etc. are used as binders in the production of watercolor paints.

gum arabic

Refers to a group of plant substances (colloids) that are highly soluble in water and are called gums or gums.

According to its composition, gum arabic is not a chemically pure substance. This is a mixture of complex organic compounds, consisting mostly of glucosidic-humic acids - for example, arabic acid and its calcium, magnesium and potassium salts. After drying, gum arabic forms a transparent, brittle film, not prone to cracking and not hygroscopic. Gum arabic, unlike oil, does not cause a change in the shade of paints, but it does not sufficiently protect the pigment from the action of light and air, since the layer of watercolor paint is much thinner than oil paint.

The main component of bee honey is a mixture of equal amounts of fructose and glucose with an admixture of water (16-18%), wax and a small amount of proteins.

In watercolor, it is better to use fructose, that is, the non-crystallizing part of honey, separating glucose from honey by crystallization from alcohol, water or acetic acid. Glucose has a melting point of 146°C and dissolves in 3 parts of water. Honey, turned into a granular mass, consists of glucose crystals. If honey is diluted with water and heated for 5-6 hours at a temperature of 60-90 ° C, then it loses its ability to crystallize.

Honey gives watercolor softness and helps to keep the paint in a semi-liquid state for a long time.

Dextrin

Dextrin belongs to the group of polysaccharide carbohydrates. Dextrin is obtained by heating starch to 180-200 ° C or to 110 ° C with dilute hydrochloric or nitric acid. Yellow dextrin dissolves easily in water and forms thick, sticky solutions. After drying, the dextrin film becomes cloudy, becomes hygroscopic, so dextrin is used only as an additive to the main binder. Watercolor paints on dextrin lie more evenly on paper than the same paints on gum arabic.

Syrup.

When starch is boiled in water containing sulfuric acid, saccharification occurs. After saccharification of starch, sulfuric acid is neutralized with chalk and the insoluble calcium-sulfur salt (gypsum) is removed by filtering the sugar solution, then the molasses is evaporated to the desired consistency.

The introduction of molasses into the binder prevents the watercolor from drying out quickly and imparts elasticity to the paint layer.

Glycerol.

Glycerin belongs to the group of trihydric alcohols. Thick syrupy liquid with water is mixed in all proportions. It is highly hygroscopic and is introduced into the binder of watercolors to keep them in a semi-dry state. It is found as an ingredient in fats and is obtained as a by-product of soap making. In watercolor, it is applied after thorough cleaning and bleaching.

Due to its high hygroscopicity, glycerin greedily attracts water from the air and gives the paint layer a wet and unstable state; with an excess of glycerin, the paint lays unevenly and in a loose layer on the paper.

With an increase in glycerin in a colorful paste, the depth of tone of some colors increases, and some, for example, cobalt blue, ocher and sienna, lose their pure light shade inherent in them and turn into darker ones - this phenomenon is explained by the high refractive index of glycerin.

Glycerin keeps the paint in a state of semi-liquid consistency and imparts softness to the paint layer, because without softeners the surface becomes covered with a network of cracks when it dries. A large amount of glycerin, i.e. taken in excess of the norm, adversely affects the light fastness of paints.

Bull or pig bile.

They are secreted by the liver of these animals. Ox gall reduces the surface tension of water, improves the wettability of pigments, and promotes even application of watercolors to paper.

A slight addition of ox bile to watercolors reduces the surface tension of liquids and improves the bond of the paint to the primer and paper.

Bile well emulsifies the oil, eliminates the tendency of watercolor to collect in drops and contributes to the uniform application of paints.

With an excess of ox bile in watercolor, the paints penetrate deep into the paper and color it.

Ox bile is prepared as follows: 0.3 liters of raw alcohol is added to 1 liter of fresh bile with 0.5% phenol, the contents are well shaken and settled for 3-5 days, and then filtered and freed from sediment.

Binder preparation.

As a binder for watercolors, vegetable glue is used with the addition of various substances of sugar, honey, ox bile, glycerin, etc., some of them lower surface tension, others increase strength and give elasticity to the paint layer or maintain paste stability for a long time.

For different pigments, an unequal composition of binders is used, since the pigments interact differently with the individual constituents of the binder.

Emerald green, containing boric acid, strontian yellow and lead yellow, containing salts of chromic acid and bichromates, make gum arabic insoluble, paints quickly harden, do not wash out with water and are not taken with a brush.

Highly dispersed pigments, such as kraplak, often cause gelatinization of paints. Weakly alkaline binders change the hue of Prussian blue, and the presence of acids causes discolouration of ultramarine.

A binder for watercolors in tubes can be prepared according to the following recipe.

I. Gum arabic binder for cadmium red, orange and yellow, cobalt blue and light green, ultramarine, kraplak, soot and zinc white. Composition (in parts by weight):

Gum arabic 40

Glycerin 15-25

Sugar or honey 2-4

Ox bile 2-3

Phenol 0.2-0 4

The amount of glycerin for kraplak and soot can be almost doubled; it is useful to add a small amount of tragacanth to the binder for ultramarine and cobalt light green so that the paint does not delaminate.

P. Gum arabic-dextrin binder for ocher, sienna and other natural pigments:

Composition (in parts by weight):

Gum arabic 30

Dextrin 10

Glycerin 15-25

Sugar or honey 3-5

Ox bile 2-3

Phenol 0.2-0.4

III. Dextrin Binder for Strontium Yellow and Chromium Oxide:

Composition (in parts by weight):

Dextrin 40

Glycerin 15-25

Ox bile 2-3

Sugar or molasses……………3-5

Phenol 0.2-0.4

IV. Dextrin binder with potassium linoleate for natural and natural umber

emerald green.

Composition (in parts by weight):

Dextrin 40

Sugar or molasses 2-5

Glycerin 15-25

Potassium linoleate 1.5-2

Phenol 0.2-0.4

Potassium linoleate prevents the paste from hardening. A glue solution is loaded into an enameled pan or tank, and solutions of sugar, honey (or molasses), glycerin, ox bile and phenol are added to it with stirring. After draining all constituent parts the mass is thoroughly mixed until a homogeneous paste is obtained.

Semi-dry watercolors in cups should contain a sufficient amount of glycerin, honey, sugar or molasses, but not too much, otherwise the paints do not adhere well and unevenly to the paper.

Binder from domestic gums.

The USSR has vast resources of various types of gum, which, due to their qualities, can be quite used in a watercolor binder instead of imported gum arabic.

The gum of fruit trees: cherries, sweet cherries, plums, apricots, almonds and others is not inferior to gum arabic in terms of adhesive properties.

Gum is released from plants in the form of transparent solid masses produced by them to cover wounds and other pathological phenomena.

During the hydrolysis of gum, a mixture of various glucoses is obtained:

gum arabic, arabinose and galactose, cherry glue, arabinose and wood gum - xylose. The composition of fruit gums includes cerazine or calcium metarabate, which does not dissolve in water, but swells in it. Gum arabic contains gum arabin, which is soluble in water. The content of cerasin in gums depends on the time of collection and climatic conditions of growth. Depending on the amount of Arabica and cerasin gums differ:

Arabica (for example, gum arabic), cerazine (for example, cherry, apricot, plum, etc.) and sorin-free - tarragant. Fruit tree gums do not completely dissolve in water, partially swell, forming a slightly gelatinous solution. Cherry, plum and blackthorn gum were used in ancient times as a binder for tempera and glue painting, which Theophilus mentions in the 12th century.

In a Russian manuscript referring to XVI century, it is indicated: “First, dissolve the gum in water, if there is cherry glue, white, clean.” Serbian manuscripts of the 16th and 17th centuries mention blackthorn gum.

Artists of our time use cherry gum for the preparation of watercolors, gouache and tempera paints.

Cherry gum.

Fergana cherry gum forms streaks weighing several tens of grams, from colorless or slightly yellowish to brown. Before use, all gum must be sorted into light, slightly colored and dark pieces and, according to their color, used for light and dark tones of paints. Almost colorless streaks can usually be collected in the spring, during the initial release of juice from the tree. The binder prepared from these influxes does not differ in color from the best varieties of gum arabic, it is quite suitable for white and light shades of paints.

The solubility of cherry gum depends on the content of cerasin: spring collection influxes with a smaller amount of cerasin completely dissolve in water in the cold and with low heat. The disadvantage of cherry gum is the difficulty of dissolving it in water and obtaining concentrated solutions without boiling. Cherry gum partially swells with water and gives viscous solutions that are very inconvenient to work with.

This disadvantage was known even to the old masters: in the written sources of the 17th century there is a description of a method for obtaining a fluid and low-viscosity glue.

In a tightly closed vessel, a solution of cherry glue is placed in a warm place for several days, while as a result of the fermentation process and an increase in acidity, the original gel-like structure of the glue is destroyed, the viscosity decreases, and the glue solution becomes as mobile as the gum arabic solution. The viscosity of the cherry glue solution can be reduced by partial hydrolysis, i.e., treatment with a 1-2% sulfuric acid solution for 3-5 hours when heated to 40-50 ° C, followed by neutralization of the acid with chalk or barium carbonate. A small amount of gypsum or barium sulfate precipitate can be filtered off.

Adhesive strength, i.e., the ability to resist tearing when gluing, domestic cherry gum is higher than gum arabic and dextrin.

High-quality watercolor paint, when diluted with plenty of water, should remain in suspension, not coagulate or separate the pigment. The rate of pigment settling is inversely proportional to the stabilizing ability of the gum, so its quality is determined by this. Gum with low stabilizing power forms unstable suspensions of watercolor, and their paint flakes unevenly on paper.

Paints prepared on domestic gums are well taken on a brush, lie evenly on paper, and when strongly diluted with water, the pigment does not flake.

Pigments for watercolor.

Watercolor paints, unlike gouache and tempera, must be transparent, which is achieved primarily by the finest grinding of pigments. Such grinding is achieved by elutriation of the pigments with water. With this method, the structure of pigments and high dispersion are preserved.

The main properties of watercolors depend on the degree of dispersion of pigments: transparency and evenness of the overlay of the paint layer.

If the pigment is coarse and not finely ground, then when the paints are diluted with a large amount of water, its particles will settle and, when applied to paper, will lie in spots and dots. Finely ground powder retains its original state, does not precipitate, and even when mixed with pigments of different specific gravity does not delaminate.

For each paint, the size of the particles is different: for natural pigments - the finer they are crushed, the brighter and more beautiful they are; for covering paints, a value of 1-5 microns is adopted; emerald green, cobalt blue and green, when coarsely ground, give the best shades, but the paint layer has a grainy surface. In watercolor, transparency depends on the degree of grinding of the pigment.

Part of the pigments, when very finely ground, loses some of their brightness and becomes lighter (for example, cinnabar), so grinding for each pigment has its own limit, i.e., the optimal grain size.

In general, pigments for watercolor should have the following qualities: purity of color; fine grinding;

insolubility in water; lightfastness and strength in mixtures;

absence of water-soluble salts.

In many respects, organic paints are superior to all other artificial and natural paints, but their rapid fading under the action of light and the solubility of most of them in water are a serious drawback that limits their use in watercolor painting. The presence of water in watercolors has a strong effect on the durability of organic paints.

Organic paints have a pure color, are transparent and work well on paper, for example, Hansa Yellow, Litol Scarlet, Krapplak Red, Violet and Pink, Monastral Blue, etc., but it should be noted that the watercolor paint layer is subject to a stronger change under light than a layer of oil paint.

A slight presence of borax or boric acid coagulates the gum and renders it insoluble in water. It is impossible to demand that the pigment be absolutely chemically pure, but in any case it is necessary to get rid of harmful impurities as much as possible, thereby guaranteeing the invariability of coloring substances during mixing, as well as the strength of watercolors in painting.

Water-soluble pigments are not used in the production of watercolors, because they easily penetrate the paper, color it and are very difficult to wash off, disrupting the overall color of the painting.

As whitewash in watercolor, you can use the best grades of kaolin or blancfix, which has high whiteness and strength in mixtures. Natural coloring earths and artificial mars are a group the best paints in watercolor due to its high lightfastness and strength in mixtures.

Cadmium red, English red, caput mortuum and a number of other pigments are also indispensable in watercolor. Carmine is a bright red paint that is very common in watercolors, but is not lightfast enough and turns black when mixed with iron-containing paints.

Manufacture of watercolors.

Watercolor paints are available in porcelain cups and tubes. The technique for the production of these types of paints does not have a fundamental difference and basically goes through the following stages of processing: 1) mixing the binder with the pigment; 2) grinding of the mixture; 3) drying to a viscous consistency; 4) filling cups or tubes with paint; 5) packing.

To mix pigments with a binder, mechanical mixers with a tipping body are usually used. For small quantities, most often the batches are prepared by hand in megallic enameled vats using wooden spatulas. A binder is loaded into the mixer and the pigment is introduced in small portions in dry form or as an aqueous paste. The grinding of watercolors is carried out on three-roll paint-grinding machines. Due to the sensitivity of some paints to iron, it is recommended to use rollers made of granite or porphyry, and replace the steel shooting knife with a wooden one.

When grinding on a paint-grinding machine, the pigment is thoroughly mixed with a binder into a homogeneous paint paste.

The quality and quantity of grinding depends on the wettability of the pigments, the viscosity of the binder, on the degree of grinding and hardness of the pigments, on the speed of rotation of the shafts and their clamping.

Coarsely dispersed pigment requires additional grinding, which degrades the quality of the paint, contaminating it with materials during the erasing of the shafts and metal dust of the knife. To eliminate this, it is not recommended to grind the paste more than 4-5 times. For grinding watercolor paints, it is necessary to have separate paint grinders for a group of pigments more or less similar in shade. One for whites, another for dark browns and blacks, a third for yellows, oranges and reds, and a fourth for greens, blues and purples.

When switching to grinding another paint, it is necessary to thoroughly rinse and clean the machine shafts.

In the production of watercolor pastes, usually dilute solutions of binders are used, since when thick solutions are used during grinding, a homogeneous paint paste is not achieved, and the pigment is not sufficiently saturated with a binder.

The frayed paint is sent for drying in order to remove excess moisture and obtain a thick paste for packaging in cups or tubes. Drying of the paste is carried out in special drying chambers or on granite slabs at a temperature of 35-40 ° C. After removing part of the water, the thickened paste is rolled into ribbons 1 cm thick, cut into separate square pieces the size of the cuvette and placed in a cup. From above, the paint is laid with a piece of cellophane and, finally, wrapped in foil and paper with a label. When producing watercolors in tubes, tubes are filled with paste automatically by tube-filling machines.

Watercolor paints in cups are easy to use, they are easy to take on a brush and retain a semi-dry consistency for a long time. The disadvantage of these paints is that they are easily contaminated with a brush when preparing mixtures, moreover, when performing big works rubbing paints with a brush in a cup gives little colorful material and takes a lot of time.

From a technological point of view, the production of watercolors in cups inevitably leads to the introduction of a number of additional operations: manual laying in cups, wrapping in foil, drying the paste, etc.

Paints in tubes are much more convenient: they do not get dirty, they are easily mixed with water without prolonged rubbing and give a large amount of colorful material. You can use less concentrated solutions of glue, which makes it possible to better clean the gum from foreign mechanical impurities. Watercolors of a more liquid consistency are more convenient to grind on paint-grinding machines and the paste is easier to pack in tubes.

The disadvantages of paints in tubes include: a tendency to thicken from drying or the action of pigments (especially poorly purified from water-soluble salts) on binders, rendering them in an insoluble state and making them unusable.

Often there is a hardening of the emerald green paste, in which boric acid is almost always present, coagulating gum arabic. To eliminate this shortcoming, emerald green should be well freed from boric acid and rubbed not on gum arabic, but on dextrin.

Strontium yellow, chromium oxide and chromium yellows also gel due to the interaction of chromic acid salts and dichromates with gum. Dextrin must also be added to the binder of these paints.

Gelatinization is also observed in watercolors, which contain finely dispersed pigments with a high adsorption capacity, mainly of organic origin, for example, kraplak.

Pigments with a high specific gravity and poorly wetted by the binder sometimes separate from the binder, and the ink paste separates. When the metal of the tubes and the pigment interact, the shade of the paint may change. Watercolor painting is transparent, pure and bright in tone, which is difficult to achieve through glazing with oil paints. In watercolor, it is easier to achieve the subtlest shades and transitions. Watercolor paints are also used in underpainting for oil painting.

Strong dilution of paints with water when thinly applied to paper reduces the amount of binder, and the paint loses its tone and becomes less durable. When applying several layers of watercolor paint to one place, supersaturation with a binder is obtained and spots appear. On slightly damp paper, a layer of watercolor paint is applied on top of the drawing.

When covering watercolor paintings, it is very important that all paints are more or less evenly and in sufficient quantities saturated with a binder.

If individual parts of the paint layer contain an insufficient amount of glue, then the varnish, penetrating into the paint layer, creates a different environment for the pigment, which is not optically similar to the glue, and will greatly change it in color.

When the paints contain a sufficient amount of binder, then when varnished, their intensity and original shine will be restored.

For a uniform and uniform coating, the paper should not be held horizontally, but at a slight slope so that the paints slowly flow down.

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