Acrylic Emulsion Paints

[Acrylic Polymer Tempera] - Painting Methods

If the artist uses acrylic polymer tempera paints thinned moderately with water, the effects of watercolor, gouache, or tempera techniques can be approximated. Sketchy effects, as well as precise calligraphic definition, can be developed according to the artist's wishes. One prominent difference from the traditional water-thinned paints is that layers of acrylic tempera paint are not dissolved or picked up when additional strokes or washes are painted over them. Many artists regard this as an improvement, but some, who are accustomed to taking advantage of the resolubility of watercolor, gouache, or tempera to alter paint passages or blend them, find that the waterproof quality of the acrylic tempera colors requires adjustments of painting procedures. Excessive thinning of the acrylic polymer tempera paint with plain water is likely to disperse the paint over too much surface, and it weakens the structure of the paint film as well as its bond to the ground. It is preferable to add some polymer medium to the water if the paint is to be thinned to a very dilute wash. This is a similar consideration to that in the oil technique [page 75 in the book] where the artist is warned against excessive thinning of oil paint with turpentine. Painters who find the natural low sheen of the acrylic temperas objectionable can alter the surface gloss by means of the matte medium.

If heavier strokes and higher textures of paint are wanted, the artist is advised to use the acrylic polymer tempera colors as they are sold in tubes, rather than jars. The tube colors have more bond and are intended to allow effects closer to those associated with oil paints. Addition of the gel medium permits increased impasto effects. As the paints are applied more heavily, they dry more slowly and can be reworked and blended for longer periods of time. However, even heavy passages of acrylic tempera paint dry much faster than do strokes of oil paint of comparable thickness, and a layer of acrylic tempera paint may be safely applied over an acrylic tempera underpainting in much more rapid sequence than is possible in oil technique. As the acrylic paint layers adhere well to each other and dry in a short time, without becoming involved in the oxidation process and the consequent changes in bulk that occur as linseed oil dries, consideration of the "fat over lean" sequence of paint films [see page 83 in the book] is not necessary.

The acrylic polymer tempera medium permits glazes and other translucent effects to be rapidly developed over heavier underpaints. The gel medium can be used to produce impasto glazes or thick transparent passages if the proportion of gel to the acrylic tempera paint is increased.

Inert additives, such as sand, silicate aggregates, or marble dust, can be combined with acrylic tempera to produce textural effects that are different from those of ordinary paints. If such materials are added to the paint, they are best mixed thoroughly on the glass slab with additional acrylic tempera medium, in order that the particles may [p. 196] be securely bound in the paint mass and so that they may remain well attached to the support. [pp. 196-197]

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