Original 1st printing 13&1/2 x 18&1/8" double-sided (*yellow pass of ink on reverse side) event/concert poster for "Fluxfest", a multi-act show/happening held at Longshoreman's Hall in San Francisco, CA on 3/31/1967. 

 Poster lists performances/appearances by Quicksilver Messenger Service, the Wildflower, the San Francisco Mime Troupe and more.

 Art by (and SIGNED in black pen on both sides by) Ida Griffin, medium flat index stock poster is in mint/near mint to near mint (A/A- to A-) condition; an absolutely GORGEOUS ARTIST-SIGNED example of this semi-obscure early-1967 SF event poster.