CHICAGO (AP) _ Playboy magazine is trading its 30-year-old staple gun for a gluepot, and the switch will mean centerfold models without punctured navels though the unstapled versions may be tougher to unglue.

Over the past three decades, men have each month ripped out the centerfold photograph of a scantily clad or nude woman to adorn bedrooms, barracks, lockerrooms or dormitories.

Removing the photo was easy, thanks to the three staples that held it in place and the magazine together.

But the magazine's 4 million readers will be turning the pages of a glue- bound publication beginning with the October issue, said Nat Lehrman, president of Playboy's publishing division.

The first major production change in Playboy's history will result in a magazine that looks much the same except for the binding, Lehrman said.

The new process will make it easier to change advertising for different geographic areas, and because it will make the magazine look more like a book, Playboy will be distinguished from competing publications, Lehrman said.

But exactly how the centerfold will be displayed for easy removal won't be decided until ''around August,'' he said.

''It will come out very easily,'' said Lehrman. ''Not easier than staples, but I'm not worried about it. Remember, there won't be any holes.''

Famous in the past for staples in their navels, the new Playboy centerfolds will be unblemished, he said.

The new centerfold will be glued in the magazine at the top of the photo, possibly perforated for easy tearing, and then folded in three sections as it is now, Lehrman said.

''There's a good chance it will be perforated,'' said Lehrman. ''It's going to be better now, though maybe a little raggedy at the top.''