Jeff Duntemann's ContraPositive Diary

I inherited a lot of things from my mother, but her intuitive knack for fine arts (she painted well and worked in ceramics) didn't come down to me, dammit. So apart from a short no-credit "enrichment" course in college that exposed me to silk screening and acrylics, I have almost no experience in painting. So while it's still unclear what sort of paints were used to paint the very early covers in Popular Electronics (see my entry for October 20, 2006) I learned a great deal about artists' paints by fielding the resulting email traffic. Consensus is that they're not classic watercolors, and may be one of the following:

• Tempera is a species of water-based paints using a binder made of egg yolk. Tempera doesn't allow the sort of deep color saturation that oil paints or acrylics do, so it can superficially resemble watercolor. If I had to guess what Ed Valigursky was using on those old PE covers in 1955, this would be it.
• Several people suggested gouache, which is a denser but much crankier species of watercolor, in which the pigment particles are larger and there is less water in the paint. Gouache is more used in geometric Miro- or Klee-style paintings or posters than in classic "fine art" paintings in which individual brush strokes combine to form a holistic image. The nature of gouache paints require that they be used quickly, suggesting a presence in commercial art. However, the drying process affects the appearance of the pigments peculiarly, and they are notoriously hard to control across multiple painting sessions.
• George Ewing was the only one to mention casein paints, which amount to pigmented and slightly thinned out Elmer's Glue based on a casein binder extracted from milk. I had never heard of these, but research indicates that they have been used since the time of the ancient Egyptians. They cover completely and can be as deeply pigmented as oils.

Michael Covington pointed out that shiny paintings are much harder to photograph than paintings having a matte finish, so commercial art would be more likely to use a non-oil process like tempera. Sooner or later I'll hear from an older commercial artist who can nail the question. We'll see.