Casein storage

Water-Based Pigments, Continued Gouache characteristics Gouache storage Gouache finishing Casein Casein permanence Casein characteristics Casein storage Gouache is opaque and chalky in appearance. Gouache should be applied in thin layers; otherwise, thick layers may become brittle and crack. Gouache is ideal for large areas of solid color and for small detail. Gouache in light colors dries darker than when wet. Gouache in dark colors lighten as it dries. You may store the gouache for short periods in an enclosed palette with a moist sponge or paper towel inside if you finish painting and have pigment left over. The moist sponge or paper towel will release moisture in the air allowing longer storage periods. Gouache has a matte surface and does not require any special finishing techniques. Casein is a water-based pigment made by combining a milk derived emulsion with oils, a stabilizer, and pigment. The formula for creating casein varies from manufacturer to manufacturer. Therefore, it is wise to select one brand of casein and use it exclusively. Casein is a relatively permanent pigment that is not rated by degrees of permanence. Casein is centuries old with only recent emulsion refinements. Casein is not fluid like watercolor and gouache and not flexible like acrylics. Casein is water soluble when wet but, water proof when thoroughly dry. Casein is opaque with some amount of white added to each color. Casein is brittle and will crack when applied in thick layers. Casein does not store well. Cheaper brands of casein lacking sufficient fungicides and stabilizers tend to mold and decompose. You should prepare the amount of casein you expect to use in one sitting. Clean your brush often during a painting session. Scrape excess paint from the palette and thoroughly clean the palette before putting it away. Continued on next page 1-59