Original 1st printing 12&1/2 x 19&7/8" concert/event poster for "Zenefit", a benefit performance (for the San Francisco Zen Mountain Center), held at the Avalon Ballroom in San Francisco, CA on 11/13/1966 featuring the Grateful Dead, Big Brother & the Holding Company (featuring Janis Joplin) and Quicksilver Messenger Service.
 
 Designer unknown (photo by Robert Boni), full-color poster image ("Zenefit") is featured in the Art of Rock book on page 184 (plate 2.181).
 
 Medium flat vellum stock poster is in very good to excellent (B/B+ to B+) condition; there is a bit of light surface dirt/pin-prick spotting in the upper left corner, along with a few stray soft handling creases/light bends hiding within the image area and a couple of thin horizontal stress bends hiding within the image area, otherwise fine.

 A very nice-looking example of this understated (and undervalued, in my opinion) late-'66 Avalon benefit poster with a fantastic all-San Francisco lineup.