Original 1st printing 16 x 22" (no Portal Productions Credit) concert poster for Big Brother & the Holding Company (featuring Janis Joplin), along with Moby Grape and the Sons of Champlin, appearing at the Ark in Sausalito, CA on 10/13-14/1967.
Art by "Licktonwalner" (?), image is featured in the Art of Rock book on page 224 (plate 2.311).
Medium flat index stock poster is in near mint to excellent (A-/B+ to B+) condition; aside from a soft moisture blot in the top right corner (about 2" square), a nearly-invisible 2" diagonal bend in the lower right corner, a tiny pen scratch ("psychadelic") on the reverse and a few small pinch/stress creases hiding within the image area, this is one of the nicer-looking examples that I have seen.
GORGEOUS original 1967 psychedelic poster from the Ark with bright, vivid colors and a top-notch double-bill.