The cover to the December 1938 issue of SPICY MYSTERY STORIES is an interesting experiment--it is a photographic cover.  Other pulps, such as THE SHADOW, also tried this idea, but (as was the case with SPICY MYSTERY STORIES) it was generally a one-issue experiment.  For SPICY MYSTERY, although the photographic cover is well done, using photographs would probably have meant abandoning the supernatural and weird elements of the covers, and spicy fans everywhere probably greeted the return to the vivid paintings by Ward and Parkhurst with a rousing cheer.