full ray-skin-wrap

Its not terribly common, but it's been done.. Usually on tantos.

Note the piece that holds the kashira in place since there's no ito - I can't remember the name of that piece though, you don't see them available as parts much.

Also check out some of the tantos here on a page from Lohman's site: www.japanese-swords.com/pages/projects.htm

So if you only have panels on your tsuka, then yes, you'll have to remove some wood for a full wrap. So you'd want to evaluate if the tsuka has enough meat to do so without weakening it too much, especially on the mune side where it tends to be the thinnest. Also, since you'll have no ito, a full wrap will be strongest if you have it go underneath the fuchi and kashira - traditionally, the ito adds strength to the tsuka to prevent splitting, so without ito, the ray skin will be the only thing adding strength, so especially important to do it right. (This may also be why you don't see it much on traditional katanas, the stresses would be much greater than on a tanto.) Also, getting the seam to line up clean can be tricky.

But not impossible, just not a slam-dunk afternoon project.

BTW, I've been pondering non-traditional ways to increase tsuka strength, such as metal support bands underneath the ray skin, etc.. On one that I'm doing right now I had a bit of a gap to fill in right behind the fuchi, so instead of filler I put a safety wire around the tsuka, in front of the first mekugi pin. In practice I don't know if it will help yet, but I figured why not if it adds a bit of a safety margin if the tsuka were to split.