I think I found what you seek. On the inside of the box of some early Scotch tapes: No. 12 - End-Of-Reel Tape Clips. "Clip securely to tape, prevent spilling or tangling in handling, storage and mailing. Fit inside reel, won't distort reels in storage. Work equally well on partial or full reels." Hope this helps. Rhett Rhett McMahon