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Art Pigments. Paints. All paints have three types of components: Pigments Media Diluents. Pigments. Pigments consist of small particles of colored compounds. Are derived from finely ground naturally occurring minerals: rocks and ores. Media.
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Paints All paints have three types of components: • Pigments • Media • Diluents
Pigments • Pigments consist of small particles of colored compounds. • Are derived from finely ground naturally occurring minerals: rocks and ores.
Media • Media serves to suspend the pigments and bind them to the surface of the object painted. • Examples are: beeswax, linseed oil, walnut oil, plaster, gum arabic and egg yolk.
Diluents Diluents such as water, turpentine, or mineral spirits allow the painter to thin the paint to the best consistency for the work.
Gemstone Paints • The only two blue pigments available to the medieval artist were the very expensive azurite and ultramarine.
Encaustic • The Egyptians, Greeks, and Romans often used beeswax as the medium for pigments. • The encaustic method was in very common use until the 8th century A.D. and is still used by a few painters today. • In this technique finely ground pigment is mixed in melted wax and applied to the surface. • Waxes are polymers composed predominantly of hydrocarbons.
Fresco • In fresco painting, the medium and the surface are the same. • An aqueous suspension of the pigment is applied directly to a wet plaster of calcium hydroxide and fine sand. • The pigment is absorbed and is bound into the surface as the plaster dries.
Egg Tempera • Until the 15th century, egg yolk was used as the most common binder and medium for paints. • Egg tempera is prepared by mixing egg yolks with a slurry of artist's pigment in water. • Enough water is added to provide the proper consistency for painting.
Oil • By the 15th century, oil paints, using vegetable oils as the medium, replaced egg tempera as the most common paint. • The oil most commonly used is linseed oil which is obtained from the seed of the flax plant. • The oil does not dry but rather is cross-linked where there are carbon-carbon double bonds in the oil.
Watercolor • In water paints, the pigments are usually very finely ground mineral-based transition metal compounds. • The vehicle is an aqueous solution of gum Arabic, a resin prepared from the sap of the African acacia tree. • This resin is a translucent water-soluble polymer. • The resulting paintings usually retain a translucent quality; they appear bright in part because the whiteness of the paper is reflected through layers of the paints.
Acrylic • These paints use an aqueous suspension of both the pigment and monomers of compounds such as methyl acrylate and vinyl acetate. • The paint does not become plastic until the monomers combine. • In a process similar to the "drying" of oil paints, these monomers are linked together by a chain reaction to form a polymer molecule that is insoluble in both water and most organic solvents.
