Sugar cubes used to be used - dropped with LSD.
Swim also had some plastic-looking acid called 'Window Panes' in the 80's and has subsequently found (see below link) out that they were made of concentrated gelatine - A great way of making up a 'sheet' which will be more stable than blotters and can be easily reproduced clandestinely.
Pure LSD is one of the strongest substances known to man and has to be diluted down massively before putting onto blotting paper. I've always presumed they sprayed or soaked the sheets with the diluted mix but not sure
Just as an aside:There has been no proven overdoses but a suspected one 1974 where some guy injected the equivelant of 1,600 hits - Man! what possessed the dude to do that????
THe 'chief chemist involved in LSD production in the 60's, the infamous Operation Julie - Richard Kemp, only received 13 years imprisonment - if he'd been in the states I bet he'd got like 200 years or something equally ridiculous.
http://www.erowid.org/references/ref...owDoc1&ID=1389
http://www.erowid.org/chemicals/lsd/lsd_dose.shtml