Wrinkle finish, Hammertone etc.
These are baked-on finishes. The object would be painted and then cured in kilns (ovens) to "set" the finishes and get the most desireable texture.
Both of these types of paints originated, I believe, in the early 1930s. There was a time when nearly all metal office machinery -- typewriters, mimeographs, calculators, safes, etc. were done in black or gray wrinkle finish (sometimes called krinkle finish).
Ditto for hammertone, although it came a bit later I think, and was not used as prolifically. I am not sure when these finishes were first used on vacuum cleaners, but the earliest examples of wrinkle finish I can think of are the Rexair Model B, and of course ALL of the Compacts up to the very end.
The earliest use of Hammertone I can think of is, there was a certain upright model of the Royal from, I think, the late 1940s that had a hammertone blue motor casing. Then of course Lewyt used it right from their first machine, gray hammertone, and Electrolux first introduced it sparingly as trim color with the Model LX and then really went for it "whole hog" with the Model E. (btw the undercarriage of the later XXX was gray wrinkle finish, and the LX was a bright "perriwinkle" blue wrinkle finish. (Not hammertone)
Both types of paint came in a variety of colors. I have seen wrinkle finish in black and gray (most common) but also gold, tan, dark brown, maroon, dark blue, turquoise and green; and I have seen hammertone in blue and gray (most common) as well as gold, dark green, dark blue, maroon, turquoise, black and white.
You can get Hammertone spray paint (don't know about wrinkle finish) but it's VERY tricky to use -- you have to find just the exact, precise thickness of the paint to get the "mottled" appearance without getting runs. And the spray painted version does not look the same as the authentic baked-on finish.
