This is a little buildalong how I do arrow passes with a mixture of stone powder (earth pigments) and epoxi. I will show this on a hazel flat bow, which I will post in an extra thread.
Bow should be done with tillering and sanding. Perhaps polished with steel wool or whatever you like.
Strengthen the surface at arrow pass area with a thinned shellac mixture, I do about three coats. This will prevent a fuzzy edging when cutting out the groove for the inlay.
Cut in the outer lines of the arrowpass with a really sharp knife or cutter. Allow to go a bit lower than top edge of the handle. The shelf and/or the leather will cover that. Now hollow out about 1-2mm deep.
On this specific bow here, I had done already the staining of the back in green and brown. For matching colors the pass comes also in these colors as a two tone inlay.
Mix epoxy, divide in a one third and a two third piece and mix it with stone powder (earth pigments). I get mine from “kremer pigmente”
http://kremer-pigmente.de/en. This is absolute the great stuff, used by artists and restorers. I use it also for paintings on my Indian bows (in this case mixed with thinned hide glue).
Fill the hole with the green mixture, take a bit of the brown and stir it in the green with a needle to get the marble effect.
Let it cure until the epoxy is getting harder (no deepening with fingernail), at this time it is easy to cut off the excess with a knife.
Let it cure completely, sand it down to the matching surface. Make it a little convex to get a minimum of arrow contact.
Polish with steel wool and finish the whole bow inclusive the arrow pass with whatever you want, I use my homemade mixture of hard oil.
Ready! Now you have a clean surface, even with the wood, you can’t feel any difference with your fingers.