I made many commercial sand-blasted signs over the years, starting in the 1970’s. The process was relatively simple: apply a thick rubber adhesive-backed resist directly to the redwood, draw your imagery, cut the resist with an exacto knife, peel away areas to be blasted. Take it to those guys out on Alvernon Way to be blasted. Once blasted, paint with enamels (and in this case, apply copper gild). Voila!

There was quite a vogue for these signs in the 70’s and 80’s but I don’t see them much anymore, a real shame as the revealed wood is beautiful, and different on every piece. Being redwood, they will last pretty much forever.