For carrying them around so you don’t bend them. I used the smaller piece of walnut that came with the glowforge. To my surprise, it was solid, not ply. Which worked out awesome because I decided to sand the edges smooth. Then I rubbed Teak oil on the edge. Its 4 layers. The front and back are exactly the same. The 2 layers in between are U shaped.
I got a little carried away on one corner… lol. But I used a small drum sander, not a belt sander. Should have used the belt sander. Oh well… it’s for me.