Truly stunning work by Richard Powers for Murray Leinster’s War With the Gizmos.
Though I’ve not read this novel, the blurb on the back cover, mentioning “strange, wispy vapors,” may have been the inspiration for cover art, which shows – well, what does it show? – a floating set of curled, filamentous, wispy threads, wafting through space, set against an ambiguous (cloudy?) olive-gray background. Though each element in his composition is crisply delineated, with distinct edges and boundaries, nothing is specifically identifiable as being either organic, or, artificial, but…there is the kind of organo-metallic “feel” to the whole, which characterizes many of Powers’ paintings.
Overall, this is an excellent example of one of the main themes Powers’ used for the cover art of science fiction paperbacks published in the 50s and 60s: A background of similar colors blended together giving a curtain-like or atmospheric feel, and, a foreground comprised of seemingly artificial, floating, curved, irregular, non-symmetric shapes. Other themes were astronauts in bulbous space suits than bore a resemblance to medieval armor, set against alien landscapes or multi-colored backgrounds, or, symbolic and abstract representations of the human form. (There were others.) Sometimes, he combined elements of these different themes within one painting.
Anyway, it’s a cool painting.
War With The Gizmos (published in the April, 1958 Satellite Science Fiction as “The Strange Invasion”, where it comprised the bulk of the issue) has been republished several times since 1958, most recently in 2019.
References
Murray Leinster (William Fitzgerald Jenkins), at Internet Speculative Fiction Database
“War With the Gizmos”, at GoodReads
Richard M. Powers, at Wikipedia