OIL ART PAINTS
Artistic paints consist of colored powder – a pigment and a binder, which holds together the smallest particles. In painting, mainly inorganic dyes are used, as more resistant, less often – organic.
There are pigments of natural origin and prepared by artificial means.
In ancient times, artists used exclusively dyes found in nature in the form of various minerals: malachite, azurite, orpiment, lapis lazuli (lapis lazuli), and all sorts of colored earth. In addition, they used dyes of organic origin, which were extracted from various plants and the simplest animal organisms – mollusks, worms.
But over time, many natural pigments were supplanted by artificial ones. For example, the blue paint of ultramarine, valued more than gold (it was obtained from lapis lazuli minerals), was replaced by cheap artificial ultramarine in the nineteenth century.
Of the natural dyes, only earth pigments have retained their value. They are usually mined when developing open pit mines. The mined rocks are dried, crushed and subjected to separation, separating the smallest particles. These pigments are durable, resistant to weathering, to light. They are not bright, but the most diverse shades, and are usually called in the place where the pigment of similar color was first found or mined: natural sienna, natural umber, Feodosia brown, evenkovskaya brown, Kudinovskaya brown, Serpukhov red, Shahnazar red, Agarak red , Gutankara purple, Zvenigorod black, Podolsky black, as well as Volkonskoit, ocher – light, golden and dark, mars brown – dark and light.
Earthen colors are known from ancient times. Thus, ocher, mixed with animal fats, was drawn by the silhouettes of animals by a primitive man.
Some earth pigments are heat treated (calcined at different temperatures), as a result of which they acquire new shades. Thus, from ocher light ocher get red, from sienna and natural umber – sienna and burnt umber.
Most of the palette of modern paints are artificial inorganic pigments. They are distinguished by a constant chemical composition and structure, brightness and purity of color, which, as in natural pigments, is caused by compounds of various metals. Therefore, they are also called artificial mineral pigments.
One of the most ancient colors, prepared by artificial means, was white lead. They remained the only and unchanged until the second half of the nineteenth century, when they learned how to get zinc and titanium white.
Nowadays cadmium is produced yellow (light, medium and dark), cadmium lemon, strontium yellow, cadmium red (light, dark and purple), cadmium orange, cobalt blue, cobalts purple (light and dark), cobalts green (light and dark), emerald green, chromium oxide, ultramarine, english red, caput-mortuum, ceruleum.
Organic pigments are inferior in strength mineral. Therefore, in oil painting, they are used very rarely, only artificial organic pigments are used, which have sufficient strength and cannot be replaced with inorganic ones due to their brightness, originality of shades, as well as high leasing properties (transparency). These include kraplak, blue and green FTs, pink and black tiondigo.
Black pigments are obtained from raw materials of plant and animal origin by calcining: burned bone, peach and grape black.
Pigments, unlike various dyes, such as those that dye fabrics, do not dissolve in water, binder and organic solvents.
Pigments can be prepared by any artistic colors: they can be mixed with glue, egg yolk, wax. Therefore, the painting technique is determined not by pigments, but by binders: emulsion (egg, casein, oil, PVA) – tempera painting, wax – encaustic. In oil painting, specially prepared drying vegetable oils serve as a binder for paints. In the production of modern oil paints, mainly linseed oil is used, and for some paints – walnut, as well as poppy and sunflower oil. Unlike flaxseed, they turn yellow less, but on drying they form less durable films. Drying oil is a complex process associated with oxidation, which lasts a very long time.
In the light, the oil dries much faster, in the dark it not only dries slowly, but also turns yellow. Dampness also slows down this process. Pigments also affect the rate of drying of the oil; some of them, for example, white lead and cobalts, accelerate this process, and kraplak, carbon black – slow down. The oil begins to dry from the surface on which a thin film is formed, which prevents the free access of oxygen and the drying of the underlying layers.