A discovery of editor Hugo Gernsback, Paul was influential in defining the look of both cover art and interior illustrations in the nascent science fiction pulps of the 1920s.

[7] Paul's work is characterized by dramatic compositions (often involving enormous machines, robots or spaceships), bright or even garish colors, and a limited ability to depict human faces, especially the female ones.

The latter featured the debuts of Human Torch and Sub-Mariner, and good copies sell at auction for twenty to thirty thousand dollars.

His most famous Amazing Stories cover is probably that for August 1927 (see image), illustrating The War of the Worlds by H. G. Wells, whose serial reprint began in that number.

Indeed, they were the first science fiction images seen by Ray Bradbury, Arthur C. Clarke, Forrest J Ackerman and others who would go on to great prominence in the field.

Arthur C. Clarke wrote that the first science fiction magazine he encountered was the November 1928 edition of Amazing Stories, with a cover by Paul.

Clarke also comments on Paul's accurate depiction of Jupiter on that 1928 cover:[10] "But the giant planet is painted with such stunning accuracy that one could use this cover to make a very good case for precognition; Paul has shown turbulent cloud formations, cyclonic patterns and enigmatic white structures like earth-sized amoebae which were not revealed until the Voyager missions over fifty years later.

"Paul's emphasis on concept, action and milieu over human figures was to continue to be a defining genre signal of SF art even when executed by successors with greater technical skill and more depth of artistic vision.