The psychedelic poster movement coincided with the rise of American counterculture, the use of mind-expanding substances like marijuana and LSD, and the explosion of the rock-n-roll scene in the late 1960s.

From about 1966 to 1970, this movement flourished in San Francisco, the center of the hippie universe. Like many of the Belle Époque posters from the early 1900s, psychedelic posters were first and foremost advertising a product–the weekly rock dance concerts at venues like the Fillmore Auditorium and the Avalon Ballroom.

But instead of delivering clear messages like traditional posters, psychedelic posters often had to be deciphered by the viewer. The main principle of the psychedelic poster was not to deliver messages clearly and directly, but rather to tease, engage, and entertain for as long as possible. Its stylistic trademarks were obscured and disguised lettering, vivid color, vibrant energy, flowing organic patterns, and a mix of cultural images from different places and time periods. The style was also tribal in the sense that if you could decipher and appreciate these posters then you were truly a member of the hippie subculture – you were hip, man.

Read more at posterhouse.org