For the twenty years after Hugo Gernsback willed a field of Scientifiction into existence with Amazing, stories didn't so much appear in the magazines as disappear into them. Thousands of stories in all the pulp fields flickered for the brief time span of a newsstand cover date before the inevitable hewing by the grim reaper of the next issue. A tiny handful of fans hoarded these magazines knowing that a lost issue was forever.
Where there's a market there's a pioneer looking to exploit it. In 1941 Phil Stong, a veteran newspaperman and novelist — his first novel, State Fair, would generate three movies — ventured into the field for the first and only time with The Other Worlds: The Best Modern Stories of Imagination since Dracula and Frankenstein. The title gives away the fantasy bent and the introduction slams us with his personal views — “there are not a dozen [interplanetary] stories with even mild originality or amusement value” — but the names include Lester del Ray, Theodore Sturgeon, Stanley G. Weinbaum, and Murray Leinster. They live up to "Modern" as well. Every story first appeared between 1933 and 1940 except for H. P. Lovecraft's 1925 "In the Belt." A handful of other now-famous hardback anthologies appeared over the next few years, as well as The Pocket Book of Science Fiction, a 1943 one-shot edited by Donald A. Wollheim.
Mystery, western, and romance buffs had the satisfaction of knowing that their favorite reads appeared in novel form. SF and fantasy fans lacked even that consolation. No writers of what we today would consider mainstream SF had more than a very long shot of seeing their works published between hardcovers before the end of World War II. By 1946 a couple of mainstream presses held their noses and cautiously entered the market, although they were more likely to fall back upon standard fantasy or dystopias like The Murder of the U.S.A., published under Leinster's real name of Will F. Jenkins in 1946. True fans wanted SF that was true SF. "[I]t always ends up with the spaceship," as Willy Ley wrote in an introduction to a Gnome Press title. Think of as many exceptions as you want, SF and spaceships were synonymous then and remain so today.
Fans with a bit of money saved up from the bounteous war years rushed in to fill the gap with small presses that would not merely reprint all-but-lost stories from the pulps but offer a new and paying market for original novels, often with beautiful jacket illustrations by top artists who appreciated the more sophisticated work that hardbacks allowed over pulp covers. Martin Greenberg wasn't first, but he thought the biggest. Gnome Press put out more books, lasted longer, had bigger print runs, and surrounded books with more promotion than any of the other SF presses, a vision financed by frequent lack of actual payments that made Greenberg the most reviled publisher in the field. To this day you have to be careful to distinguish the noted anthologist Martin H. Greenberg from the noted crook Martin Greenberg. Greenberg meant well. Bad luck and bad timing were his downfalls more than outright larceny. He owed so much to his printer that the printer kept him in business long after the bottom had fallen out just in the hope that the next book or the one after that would finally make enough money to cover his bills.
None of this could be known at the beginning. Although his first two books were the original fantasy novel The Carnelian Cube, by L. Sprague de Camp and Fletcher Pratt, and The Porcelain Magician, a collection of older fantasy tales by then-big name Frank Owen, the field started taking note in 1949 with a string of major titles: Pattern of Conquest, an SF novel by George O. Smith serialized in 1946 in Astounding; Sixth Column, the revised edition of Robert A. Heinlein's 1941 Astounding serial under his Anson MacDonald pen name; William Gray Beyer's Minions of the Moon, first published as a three-part serial in Argosy in 1939; I, Robot, Isaac Asimov's collected robot stories; and Cosmic Engineers, another 1939 serial, this one from Clifford D. Simak and originally published in Astounding, all by the end of 1950. Greenberg himself edited an anthology of — what else? — space stories, titled Men Against the Stars and including such names as Asimov, Leinster, A. E. van Vogt, Hal Clement, C. L. Moore and Henry Kuttner writing as Lewis Padgett, and E. Mayne Hull. Both C. L. and E. Mayne were woman (probably: some evidence can be found that van Vogt wrote the Hull stories that wound up being published under his wife's name), and so were Gnome novelists Wilmar Shiras, Leigh Brackett, and Andrew North (Andre Norton). Despite that, Moore, Shiras, and Brackett were forthrightly referred to as shes on the flaps of their books and Judith Merill did a series of anthologies (and had a story picked for one of Greenberg's) No evidence exists that these women had to hide their identities because of prejudices among editors or readers.
Gnome would go on to further triumphs of publishing with names that included Arthur C. Clarke, Frederik Pohl, Jack Williamson, E. E. Smith, James Schmitz, James Gunn, Robert Silverberg, Poul Anderson, and Gordon R. Dickson, and award winners like Mark Clifton & Frank Riley's They'd Rather Be Right and Clifford Simak's City. On top of that add five more anthologies of SF stories by Greenberg, one by Groff Conklin, and the first four editions of Judith Merril's Best of the Year series. Wait, there's more. Greenberg's fantasy line included Talbot Mundy and the first five Conan the Barbarian story collections to see hardback with two more books of additional Conan material added by de Camp.
Greenberg also used most of those top SF artists for cover work, abetted by his early partner David Kyle, who did covers himself and contributed a map of Conan's Hyboria that is the standard to this day. Other artists whose names define the era include Hannes Bok, Edd Cartier, Ed Emsh, Ric Binkley, Mel Hunter, Wallace Wood and Frank Kelly Freas. (Whose name was given six times! as Frank Kelly Frease. Honestly. A whole page could be written on Gnome's weirdest typos.)
I started collecting Gnome books 40 years ago. I finally have them all — 86 hardback titles, 1 slipcased special edition, 4 Armed Forces trade paperbacks. And three of their four? (nobody's quite sure how many) fantasy calendars, the six issues of the newsletter they sent out, and a smattering of other ephemera. Since I hated to stop because of the mere technicality that I had it all, I've been trying to track down all the variant editions, of which slightly more than 70 are known. Greenberg used a printer who was cheap but demanded a minimum printing of 5000 copies. When Greenberg didn't have enough money to bind that many copies or didn't think he could sell them quickly, he stored the printed pages at the printer and ordered bindings as needed. He used whatever binding stock — cloth or boards in any of a zillion muddy colors — was available (or maybe on sale) at the time. Some Gnome books are known in as many as five different bindings. Every once in a while, the back cover got reprinted. Once or twice the front cover did. It's a feast for collectors while simultaneously being a nightmare. What's most wonderful about it is that it can't ever end for certain.