Pendulum Publishers, Inc.

Pendulum vintage adult magazines (late 1960s - mid 1970s) was a line of softcore-to-early-hardcore erotic publications produced primarily under Pendulum Publishers, Inc., with closely related imprints Calga Publishers, Gallery Press, SECS Press (Sex Education Clinical Series), and later Edusex.

These magazines captured the sexual revolution era with swinging, group sex, lesbian, gay, fetish, and sexploitation film themes, featuring explicit photo spreads (mostly black-and-white with color centerspreads or sections), short fiction, articles, and captions.

Pendulum library largely transformed by the mid-1970s amid the shift to full hardcore (post-Deep Throat). Titles were thematic and self-explanatory. Regular series often ran multiple volumes/issues and annuals issues with compiled prior content.