Acrylic Emulsion Paints

[Acrylic Polymer Tempera]

Artists' colors utilizing an acrylic polymer emulsion as a binder have been on the market since the early 1950s. Some of the well-known trade names for these colors are Liguitex [Binney and Smith, Inc.], Aquatec [Bocour Artist Colors, Inc.], and Politec [Politec Co.]. The manufacturers sell their paints packaged in metal roll-up tubes, polyethylene squeeze bottles, and glass or plastic jars ranging in capacity from two ounces to one gallon. The artist thins these paints either with water or with one of the mediums supplied for this purpose by the manufacturer. The binders and the polymer [p. 191] painting mediums are based on an acrylic emulsion such as the one produced under the brand name Rhoplex [Rohm and Haas Co.] AC-234. This material is milky white when liquid, but when it is painted out in a thin layer the water in the emulsion evaporates, and a clear film is formed. The drying process does not involve oxidation. Like most water-thinned paints, the acrylic polymer emulsions dry quickly, but unlike other water paints they harden to a film that is highly resistant to water. Used straight from the tube or jar, the paints usually dry with a slight gloss, but the degree of gloss or dullness can be controlled by use of one of the acrylic polymer painting mediums. Although some samples of paint hardened in the containers during the years when the products first appeared on the market, most of the colors sold today keep reasonably well for water-thinned paints, and they are not harmed in their containers by cold temperatures. Because the binder and painting mediums dry to clear colorless films, and the colors of the pigments are not changed by this binder as they are by such media as the linseed oils, the paints yield tones of great clarity and intensity. Tests performed since 1960 indicate that the acrylic films do not darken progressively with age, whereas films using linseed oil as a binder must, to some extent, suffer some discoloration. Oil paint films become more brittle with age, often cracking or powdering as they continue to oxidize, but dried films of acrylic polymer paint appear to remain very flexible. [pp. 191-192]

[Kay, Reed. The Painters Guide to Studio Methods and Materials. Englewood Cliffs, NJ: Prentice-Hall, Inc., 1983.]