While [Jasper] Johns quite literally put encaustic on the map, a resurgence of wax as a medium had already been under way. In Mexico in the twenties, Diego Rivera used encaustic for easel painting and murals. In New York in the late thirties, Arthur Dove painted with wax emulsion. At the Boston Museum School in the forties, Karl Zerbe, who had trained as a chemist in his native Berlin, experimented with numerous formulas before settling on a wax/resin mix (eight parts beeswax, one part damar resin, one part Venic turpentine). His students included David Aronson, who went on to teach at Boston University, and Reed Kay, who wrote The Painter's Companion: A Basic Guide to Studio Methods and Materials.
Zerbe and Arnoson were two of the artists featured in an earlier book, the now classic Encaustic Materials and Methods by Frances Pratt and Becca Fizel, published in 1949. This modest volume was a first, offering not only recipes and technical advice from practicing artists, but historical precedents. A contemporary reader might find the text overly concerned with esoteric ingredients - "montan wax," "copal gum," "oil of spike" - but for an artist at that time, and even for decades later, it was the foremost source of information about encaustic.