A very rare first printing of the sought after poster "Trip Or Freak" advertising a San Francisco concert on Halloween, 1967 featuring the Grateful Dead, Quicksilver Messenger Service and Big Brother & The Holding Company (featuring Janis Joplin.) This legendary poster is a collaboration between Stanley Mouse, Alton Kelley and Rick Griffin. There's a legend that many of these were cut up for the hundreds of small skulls making up the background–which were impregnated with LSD and sold as blotter acid. This example is in excellent condition; it was invisibly removed from a backing by paper conservation expert Chris Fennell of Chameleon Restoration, who flattened three creases (likely from rolling) and did some extremely minor touch up. It looks near mint now, with some very tiny rounding to the corners. A beautiful example of a rare and highly collectible poster from the classic era of San Francisco rock. 14 1/4" x 28 1/8".