The art on LSD sheets. I so far have 3 sheets
The Hofmann print one of the most popular prints of the 21st century. There are several variations
Getafix the popular European print featuring a wizard.
Not sure the name of this but when you check out the Wikipedia page for LSD they use this print as an an example
A free sheet the vendor sent me featuring Hofmann on triangle shaped hits
http://www.blotterbarn.com/
http://www.key-z.com/special.html
https://www.wired.com/2016/02/inside-the-lsd-museum-that-the-dea-somehow-hasnt-torn-to-the-ground/
https://shakedowngallery.com/