Unknown 1960's-era printing 33&1/8 x 21&1/4" 1967 silkscreen merchandise/headshop poster (artist-licensed and printed by Personality Posters, Inc. of New York), "Keep on Truckin";

 Art by R. Crumb, medium-thick flat vellum stock poster is in near mint to excellent (A- to A-/B+) condition; aside from a tiny edge nip tear/bend in the upper left corner tip, a hairline-thin vertcal bend in the upper left margin, a hint of surface wear (a few thin scratches/pin-prick scuffs here and there) and a couple of tiny mouse bite nips along the upper right margin, it is a mostly-clean example of this ICONIC 1960's R. Crumb image.

While there are NUMEROUS reprints/bootleg editions of this poster, none of them (that I've seen) have Crumb's signature or any printer's credits (this edition has both).