I have been replacing tips for my cues and for those of my friends for a few years now. One of my friends bought an older cue at a garage sale that had a really thin worn tip and asked me to replace it. The only thing that's odd about it is the tip has a thin (maybe 1/32") black disk between the ferrule and the tip. I asked a few people at our pool league about it and one said that some tips used to come premounted on a plastic backing and I should remove it before I put the new tip on. I have a Rapid Cue top sander and I could easily sand it off, but since I've never seen this before I thought I would ask a larger audience first. Not knowing what this disk is called its been difficult to search for information. Also this isn't a screw on type tip, just a normal tip on an old Adam Cue. I can include a picture if I'm not explaining this well enough.