REVIEW The clean-cut man in the portrait looks straight ahead with knowing eyes, his leather jacket open — an invitation, perhaps? — revealing a muscular torso and chest, on which is tattooed a purple butterfly. The painting's mix of leather and a little lace sums up much of the art and life of Chuck Arnett, a habitué and documenter of the leather bar scene during gay liberation's golden age in the 1960s through the late '70s.

The majority of Arnett's work was inspired by and made for the bars and back rooms he frequented. Sex, drugs, and rock 'n' roll are unapologetically front and center, a potent mix reflected in styles that veer wildly from rough sketches of men fucking in bathhouses to carefully executed psychedelic oils. The surviving fragments and photos of Arnett's large-scale painted murals for the original Stud, the Tool Box, and the Detour — and related ephemera like patchwork wall hangings of tanned scraps instructing "Eat It!" — not only tell the story of Arnett's transformation from Southern ballet sissy to acid-dropping public-sex advocate but also illustrate the radical changes the gay community underwent between The Wild One (1953), Stonewall, and Harvey Milk's murder.

Arnett's national coming-out as a painter arrived when Life included a photograph of his Tool Box mural in its landmark 1964 spread "Homosexuality in America": the bar's leather-clad denizens mirrored Arnett's black-and-white swathe of butch fauna. Five years later Arnett would quote himself in a massive Day-Glo mural for the Stud — sadly, reproduced in photo only: a panorama in which Marlon Brando clones warp into a cosmic chessboard dominated by an American Indian and a Sahasrara chakra. In a corner of the piece one surviving component is an appropriately phallic biker, whose badge says what could have served as Arnett's maxim: "Freak Freely."

LAUTREC IN LEATHER: CHUCK ARNETT AND THE SAN FRANCISCO SCENE Through April 26. Tues.–Sat., 1–5 p.m. GLBT Historical Society, 657 Mission, no. 300, SF. (415) 777-5455, www.glbthistory.org