What to put under Japanese handle wrap for thickness?

[Chiro75]

On a 1/8" steel knife, I assume unless I'm going for a real thin/low profile setup, that I need to put something thin under the wrap and rayskin to add a little thickness to the handle. This would be a full tang knife. It doesn't seem to make sense to use a nice piece of wood or other handle scale material. Is it okay to use a thin piece of something cheap like pine, since it won't ever be seen? Or on 1/8" stock is rayskin and wrapping enough?

 

[howiesatwork]

Maple, poplar, birch, beech, Micarta, epoxy, bamboo.
The list is long. The only woods I wouldn't use are ones high in tannin, such as oak.

 

[dfarmerknives]

Depending on the height of the handle, I do not use any underlay. I have used athletic shoe laces, inpregnated with epoxy as a underwrap. Using the same color overwrap, it is almost impossible to see.

Nylon string is good, too.