The walls of Mark Mccloud's San Francisco home are covered in LSD blotter art. He calls his collection the "Institute of Illegal images", and you can visit for free. Here is a 2016 interview with Mccloud inside of his home. He's a fascinating character. All of the artifacts in the institute have a backstory, such as "a framed blotter print of a telegraph sent by Allen Ginsberg pleading for the release of LSD pioneer Timothy Leary (SF's Institute of Illegal Images is like an LSD museum )." Mccloud nearly got a life sentence in prison for owning so much blotter art, but he managed to get out of trouble and continue curating his incredible collection. Check out some images and prints from his collection online here.