Acrylic Emulsion Paints

[Acrylic Polymer Tempera] - Care and Display

The acrylic emulsions used in the acrylic polymer paints, varnishes, and primings dry as films that remain pliable and adherent. However, it may often be noted that the surfaces of such films, even after they have dried thoroughly, tend to show a very slight tackiness. If a dried acrylic polymer tempera painting or primed surface is kept in contact with another surface, especially under weight or pressure, it is liable to adhere strongly to that surface. For example, acrylic primed panels stored face-to-face in stacks may sometimes stick to each other, and when the panels are pried apart, small chips of the acrylic gesso may be pulled off the edge of the panel. Because of its tendency to adhere to surfaces with which it is in contact, an acrylic polymer tempera painting that is to be framed under glass in the manner of a gouache or watercolor should be separated from the glass by a mat or by an insert of molding to eliminate the possibility that it may stick to the glass surface. [See Framing, pages 238-44 in the book].

Acrylic tempera paintings can be cleaned with water and mild soap. Organic solvents such as benzine or turpentine should not be used to clean acrylic pictures since these solvents may injure the paint surface. A final varnish over an acrylic polymer tempera painting serves to protect the picture against accidental abrasion or scratching. It may also be used to bring the surface to the degree of gloss or matte quality that the artist may desire. However, varnishes such as dammar or mastic dissolved in turpentine should not be used as final varnishes or acrylic tempera pictures since their eventual removal in cleaning processes would involve solvents that might be dangerous to the painting. The acrylic polymer medium makes an effective final varnish which dries with a glossy surface.

If a matte surface is desired, it is best to use one of the acrylic matte varnishes made by the manufacturers who sell the acrylic tempera paints. The matte medium and the matte varnish are not identical, and the matte medium is not recommended as a final varnish since it may appear frosty when it is applied over deep tones. The varnish can be thinned with a little water, if necessary, and it is applied with a wide soft hair brush. Although [p. 197] it may seem a little milky as it is applied, when it dries the matte varnish or acrylic polymer tempera medium will be clear.

Since acrylic tempera paintings can resemble in their optical qualities the effects of oil paints, egg tempera, or various other techniques, it is wise to indicate on the back of the picture that the painting was done in acrylic emulsion tempera, that it ought not to be cleaned with organic solvents such as turpentine, and that it can be cleaned with mild soap and water. [pp. 197-198]

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