Extremely rare test-run poster for an “Acid Test Graduation” party held at San Francisco’s Winterland Ballroom on October 31, 1966. Printed on an off-white 12.5 x 20 Esalen Institute seminar flyer and designed by Allan “Gut” Terka, a Hells Angel, Merry Prankster, and former Blue Cheer manager, the poster shows a superhero figure with mortarboard above bold lower text promoting the scheduled acts and speakers: Grateful Dead, Merry Pranksters, Neal Cassady, Caliope Co., Ken Kesey, and A.A.A (Anonymous Artists of America). The poster notes the appearance of “Many Guest Stars” and asks the prospective attendee: “Have you passed?” In very good to fine condition, with overall wrinkling and creasing.The Acid Tests were a series of parties organized by author Ken Kesey to promote the use of, and advocacy of, the psychedelic drug LSD. The final event, scheduled for Halloween at the Winterland Ballroom, was canceled when promoter Bill Graham caught wind of a plan to put LSD in the venue's water supply. Kesey quickly relocated the graduation ceremony to a dance company’s warehouse on Harriet Street in San Francisco, where Neal Cassady handed out the diplomas to those in attendance. Although the Grateful Dead were initially listed on the poster, the band later committed to play that same evening at the Dance of Death Costume Ball held at California Hall along with Quicksilver Messenger Service and Mimi Farina. With the final versions of these posters among the most desirable of all Kesey-Grateful Dead memorabilia, this preliminary 'experiment' example looms as a true psych rock rarity.Format: Poster