Unknown 1970's-era unofficial printing 14 x 21&3/4" concert poster for the Grateful Dead appearing with Blue Cheer at the Shrine Exposition Hall in Los Angeles, CA on 7/11/1968. (*image is an post-show commemorative originally created by Rick for the California Graphics Exchange)
Art by (and SIGNED in gold paint pen by) Rick Griffin, medium glossy stock poster is in near mint to excellent (A-/B+ to B+) condition; a few stray fingerprints, a couple of tiny edge/corner bumps, a thin diagonal crease in the top left corner tip and a soft horizontal bend in the upper right margin, otherwise fine.
This is a fairly intriguing item; I recall seeing a couple of these glossy-stock posters years ago (in the old Psychedelic Solution inventory) and wondering where they fit into the scheme of things... they definitely pre-dated the 1986 PS reprint (that one has the full design, unlike this one), but as to the origin... tough call. Seeing as Rick went ahead and signed this one, it doesn't appear as though it bothered him that this wasn't an "official" printing (which makes it that much more amusing), but it's definitely an oddball.