When rewrapping a tsuka, I often find myself wondering, "Who originally wrapped this?" "How did they wrap this?" and, "What materials did they use?" Any restoration or repair work is risky, especially without a sound understanding of the initially work.
A case in point would be Dave R.'s tsuka. Recently, I found myself restoring, and then, within a relatively short amount of time, restoring my restoration. Let me explain.
To begin with, I received a tsuka that needed a new wrap; it wasn't in terrible condition, but the ito wasn't as tight as possible either. As I disassembled the old tsukamaki, I removed the base paper strips that were originally placed along the "ha" and "mune" edges of the tsuka and found a thin film of something like rubber cement... I couldn't figure it out.
Then, during the tsuka prep work, I tried to cover the film with a simple paper strip, using first rice glue then Elmers, but neither would stick. I brainstormed with a couple of other wrappers and it was suggested that I try paper tape, like the type used on bandage dressings. That seemed to work (below is a shot of Dave's tsuka with my first tsukamaki).

Not long after Dave started using his sword with the new tsukamaki, he noticed the ito shifting in a couple of spots (see picture below).

Dave contacted me, I had him send it back. Whatever kind of glue or sealant the original wrapper had used on the tsuka was the cause of all later problems. When I unwrapped it the second time, the paper tape I had used was gone! It had disintegrated and in its place was a waxy film that was slippery to the touch.
This time I used a small cotton swab and acetone to remove all remnants of whatever that original "stuff" was.
I also wrapped it extra tight, so tight in fact that I was able to fit in an extra crossover onto the tsuka; my first wrapping had 17 crossovers on each side, but now, using the same weight ito, there are 18.
Now I am anxiously waiting for some performance feedback from Dave.