Based on photos and videos, it seems that Kurt mostly used orange Dunlop Tortex picks, which are .60mm thick. However, photographic evidence mostly dates back to the ‘In Utero’ tour, so it is possible that Kurt used a different brand/model during the earlier years.
Watch the November 19, 1991 show In Rome, Italy on the Nevermind European Tour on “Come As You Are” there’s a close-up of Kurt and you can see Kurt is using these Orange Dunlop 60.mm picks
https://www.youtube.com/watch?v=BXlLqA2cj4s buenos aires 10-30-1992
go to 40:50, you can see these picks on kurt’s mic stand again (they look pinkish due to stage lighting i presume)
You the man
this was all kurt cobain used, the reason he used the is because they are very thin so its easier and more comfortable to strum the guitar but also just the right size to play single strings so this an all round comfortable pick, for songs live territorial pissings and scentless apprentice these make them much more comfortable.
i use these picks myself and would highly recommend no matter what level you are at.
they come in a pack of 12 and with a dust like substance on them for better grip at the start which will fade into the picks and give them a highly enjoyable feel until the end of eternity!
From louie