mike17...I've never ever heard of Slingerland installing the wrap on the plies and then inserting into the mold. I know that Ludwig did this and it's easy to tell by the way the wrap goes into the overlap. As for Slingerland, I've never seen a drum wrapped this way. To my knowledge, the wrap was always installed on the completed shell.-Mark

Before '57 or so Slingerland wraps do go into the scarf joint, exception being snare drums, if memory serves....and if that's what's being discussed....??

I have re-wrapped 100s of kits and run the drum wrap company; Walopus. (Link in my signature)Most wraps fall between just under 20 mil for standard factory-type wrap and up to just over 35 mil for glass glitters and other thicker wraps.95% of the time even the thicker wrap will fit just about any manufacturer's shell.Issues mostly arise due to some shells not being perfectly round. Even if there's enough clearance in one direction, the head may not clear the wrap at the other direction. It can in these cases usually be forced on by squeezing the shell so it's round while installing the head, but the end result is a very difficult tuning process.

http://www.vintagedrumguide.com/drcjw/article_3_shells8.html