Erik Davis joins Kate Wolf to speak about his latest book, Blotter: The Untold Story of an Acid Medium. The book is a study and history of the emergence of acid blotter paper from the late 1970s to the present day. It charts not only how the distribution and legal definition of LSD has changed over the decades—along with shifting cultural attitudes towards the drug—but also how blotter makers reflected these changes in their designs. The book examines the many recurring themes and aesthetics of blotter from cartoon characters, underground comics and advertising, to religious and political imagery, as well as associations with modern art movements like pop and minimalism. As psychedelics move closer to legalization for therapeutic purposes, Blotter is a reminder of the freak culture, anti-establishment origins of LSD and the inventive and playful path one of its main mediums has cut across countless minds over the last half century.