Check out this rare Vulcan Gas Company poster on our friend's wall. It promotes a series of shows featuring Shiva's Head Band, Conqueroo, Afro Caravan and the Golden Dawn. Show dates were December 22 - 31, 1967. This fabulous psychedelic image, "PSYCHO BUBBLES", was designed by Gilbert Shelton, and is referred to as VG 9 in the Vulcan Gas series. For good measure I am throwing in the handbill too.
To me, this poster is obviously a nod to the Vulcan's Light Show. Practitioners would squeeze colored oils between two glass clock-faces on an overhead projectioner.