It is looking good. If your forest texture is something like plaster stippled atop the wood surface, you could "scrape it flat" in little patches to permit lettering. Or if it is supposed to be roughened wood, your craftsman-carpenter-cartographer might just have left little rectangular patches unroughened, to simplify labeling. Or you could pin little scraps of parchment (simulated) atop the forest, bearing the labels...