‘Pulp’ is a pejorative term for certain kinds of fiction (and its authors). Pulp magazines began to appear during the First World War or earlier and got their name from the fact that they were printed on wood pulp, which gave the content a coarse, grainy appearance. They were about 7 x 10 inches in size, had gaudy covers and comprised about 120 pages. They published short stories and occasional extracts from novels. During the 1920s, they became extremely popular (there were well over 200 in existence) and they remained popular in the 1930s. Eventually, television brought about their demise.
Pulp magazines published detective stories, various kinds of horror stories, and many tales of the weird and wonderful, the supernatural, and the fantastic. Well-known examples were The Black Mask, Dime Detective, Thrilling Detective, and the Detective Story Magazine, Oriental Stories, Planet Stories, Spicy Detective, Startling Stories, Thrilling Wonder Stories, Unknown, Weird Tales. Science fiction stories also became very popular through the pulp magazine, especially Amazing Stories (first published in 1926), though this was by no means the first SF magazine. . The most successful pulp magazines were Argosy, Adventure, Blue Book and Short Stories, collectively described by some pulp historians as “The Big Four”.
Pulp literature is basically trash, or something very close to it; what Aldous Huxley would have described as ‘inconceivable twaddle’ or ‘semi-minus epsilon’. It includes the kitsc, potboilers, poor Westerns, many novelettes, the lower forms of crime fiction, and third-rate sentimental romances.