Earlier quoted context omitted.
> A thumbprint is a method of consuming a massive amount of lsd, where a massive (relatively, compared to a blotter dose) amount of lsd crystals are made into a small pile, pressed on with a thumb, and then the thumb into the mouth. The ROA is still oral.
Sure, but the accounts of thumbprinting I've read made it seem like there is a strong sensation almost immediately after touching it. I also know people who have described a contact high from laying sheets of LSD. Hmm... I could be wrong though.
Don't believe all written on internet (says internet comment :))