Original 1st printing 14 x 14" Sound City Records (no credit) promotional poster for "The Acid Test", an album featuring a series of LSD-inspired conversations/rants, random sound effects and bits of music (performed by the Grateful Dead) recorded and sequenced by Ken Kesey and Ken Babbs of the Merry Pranksters in January of 1966.
 
 Designer unknown/not credited (presumably Kesey), medium-thin flat vellum stock poster is in decent (B/B-) condition; there are tack holes and tiny pin-prick spots in all four corners, along with a small chunk of paper missing from the lower left corner tip, a diagonal tape pull (with a bit of paper thinning) in the upper left corner tip, a 2" diagonal bend in the lower left corner, a set of semi-flattened horizontal/vertical folds with a tiny hole at the intersection in the middle of the image area (item was folded into 1/8ths and subsequently flattened), a bit of mild paper toning, a light to moderate amount of handling wear/creasing, tape remnants and a bit of pencil scratch on the reverse... a well-traveled example, but it's all there.

INCREDIBLY SCARCE (only a couple of these known) early-'66 Kesey/Grateful Dead Acid Test artifact from a VERY obscure one-off Prankster project.