As if 20th-century gimcracks such as cassette novels, comic books, movie novelizations and television magazines weren't already slicing it pretty fine, the great pie of literacy now has to be divided again.

The new wedge, which is starting to make mouths water, from West Coast movie producers' to East Coast publishers, is called Fotonovels.

Fotonovels are standard-sized paperback books with titles such as "Grease," "Heaven Can Wait," and "Close Encounters of the Third Kind." they hold about 400 frames from the movies of the same names, are printed in color on 50-pound glossy stock, and are accompanied by word balloons, comic-book-style, bearing the script.

They sound a little ridiculous.

"How are you?" says John Travolta, in his word balloon from "Grease."

"Fine, thanks," says Olivia Newton-John, thus proving that movie scripts don't make any better reading than movie stills make viewing.

The Fotonovels glady jettison nuance for impact.In "Heaven Can Wait" when dialogue fails to alert the reader to emotions, the editors insert "ENVY!" and "EXTREME GREED!" over the villains' heads. Three pages later we get "EXTREME ENVY COMPOUNDED BY ABSOLUTE GREED!" The pages are littered with BOOM! TINKLE! - sound effects that read like comic-strip stuff from 40 years ago, before the buddabuddabudda of Marvel Comics' machine guns (and the kipyeowwwwww of the ricochets.)

Somehow, though, a campy cheer emerges.

Fotonovel Publications' Herb Stewart, along with co-founder Laszlo Papas, has put it all together, with a price of $2.50 a copy, "Grease," the best-selling volume to date, has amassed three printings totaling 600,000 copies, with another printing under way. Also in the series are 12 titles based on "Star Trek" footage, and "Ice Castles." based on a forthcoming movie about a blind ice skater.

"There's some older stuff I'm interested in now," says the 35-year-old Stewart, who quit a career as a classical guitarist in Europe to return to his native Los Angeles and seek his fortune.

"I want to do 'The Godfather,' I'd like to do the Elvis Presley films - they're awful, but people want them. I'd like to do the 'Pink Panther' movies, the James Bonds. It's bubble gum stuff, surc. I love it. For a film buff, I'm probably insulting him. But some day, I'd really like to do something like 'The Blue Angel,' when we get bigger, with more money."

Fotonovels are an American version of the popular Italian and Spanish fotonovelas - black and white magainzes with original story lines, heavy on gangsters and romance. Obscure actors pose for the photographs.

"That's where the idea came from," Stewart says. "My idea was to put established stars into the format. The star appeal means something, all over the world." So Stewart has sold rights for translations into Spanish, French, Flemish, Arabic and Japanese.

Not that influences and precedents have been lacking.

Says Jack Nachbar, professor of popular culture at Bowling Green State University in Ohio, "Movies and prints have been feeding off each other ever since comic strips and movies developed simultaneously at the end of the 1890s.

"I have a copy of the novel 'The Klansman.' from 1915, in which they'd inserted pictures from the movie 'Birth of a Nation.' which was based on it. Pulp literature was the basis for a lot of movie serials. In the 1950s, I remember a Dell comic version of the movie 'Samson and Delilah,' among others. And ever since 'Love Story,' in 1970, we've had all these novels written from screenplays, rather than the reverse. The new Fotonovels are a highly commercial form. I think they'll continue to depend on hit movies for their appeal, so I don't foresee them being done fromscratch."

Avon Books tried something similar a few years ago with the Film Classics Library Series, featuring oversize versions of movies such as "Casablanca," "Stagecoach," and "The Maltese Falcon." They sold for $4.95 - when they sold.

"When you're doing Buster Keaton in 'The General,' you can't expect to sell a lot," says Robert Wyatt, editorial director at Avon. "We talk about doing something like the Fotonovels every few weeks now. But you have to realize you have to start with a lot of copies when you print that much color. If you print 500,000 you could eat 300,000 books if it doesn't go."

In Hollywood, however, where nothing fails like success. Stewart is less worried about bad sales than an avalanche of competition from studios, producers and publishers.

"They may deny it, but all the major publishers are considering this," says Stewart. "I know what's coming off."

At Paramount, production vice president Nancy Hardin says Fotonovels have "a big future. 'Grease' has pushed everyone over the edge in their awareness. I know Herb Stewart is depressed about it. But the producers are much more spinoff conscious than they've ever been, and let's face it, the world is getting much more visual and non-linear."

At David Obst Books, a division of Random House, david Obst uses aObst Books, a division of Random House, Davd Obst uses ad under rocks to say: "These things are a great advancement in the cause of belles lettres. They'll work until a few fail, and then they'll disappear."

But at Bantam Books, which published the Star Trek Fotonovels after Herb Stewart put them together, Terry Bromberg says, "We're very pleased with the way they're going," and points out that Bantam has "a new series called Skylark Illustrated Classics - very classy drawings with word balloons of titles like "Treasure Island' and 'Frankenstein.'"

Once, of course, books like that were only for kids and people who didn't like to read. Nowadays, presumably, some people might find even Fotonovels hard going. But for them, of course, there are always the movies, which strangely enough are a step up in prestige from the books.