Here is a great little collection of trippy psychedelic rock posters from the 60s featuring bands like The Doors, Jefferson Airplane and Pink Floyd to name a few.
I really love the simplicity of these designs. 40 years before the advent of Photoshop artists like Rick Griffin and friends were pumping out spectacular hand crafted works of psychedelic brilliance.
Sixties psychedelic art went on to inspire so many great artists and musicians over the following decades. I see definite echos of the original 60s style in modern day graffiti and psychedelic visionary art too. I suspect they were also used as general trippy pictures to look at when high back then too.
> You might also like this psychedelic pictures collection