Years ago they used virgin clear heart redwood to make sandblasted signs. Nowadays they use cedar and other materials.
I have been scoring these old signs over the years and I planed one down this morning. beatiful vertical grain redwood.
I find the old signs at auctions and salvage yards. The big one leaning against the tree is 12 feet long and around 30" wide.
Great stuff for stringers,fins,tailblocks and skateboards.