I appreciate the viewpoint, but we don't call plywood "wood" because it isn't wood. If we were to develop a metric, the % of mass of the finished product that i

I appreciate the viewpoint, but we don't call plywood "wood" because it isn't wood. If we were to develop a metric, the % of mass of the finished product that isn't wood would be a reasonable one. The problem with saying it's 38% bamboo is it implies it's in some meaningful sense made out of bamboo. It's not. There isn't a way to go in there and cut out a piece and have it be bamboo--unless it's really, really small (maybe). Whereas it's totally possible to take a piece of wood from an old piece of furniture, surface it four sides, and have essentially wood (albeit a little smaller). I think also that you're a little off on two things: 1, common wood surface treatments are < 5%, and 2, composites vary but 60/40 fiber/resin by mass is a reasonable place to start.