Long time lurker, and haven't posted much, but I need some advice when wrapping scabbards in leather. I recently made my first wooden core for an old Windlass European Sword. It turned out OK. Now the problem arises when I wet my leather, to wrap around the core. I've done a few swords before (this is my 3rd, so not many) and have had varied success.
I use masking tape, with the adhesive side up, so as not to touch the leather. I used tape because it's flat, and I can wrap it pretty tight without any wrinkles. It actually works well. The problem is where the masking tape isn't...where the leather is still exposed (like a small gap). The water seems to darken the leather here.
Should I use something other than the masking tape? Or is there something else wrong? I find it odd that where the leather is exposed to air, that is where the stains happen...
Wood core and re-leathered hilt:

Stains...

