I sprayed my trailer's wood floor (and one foot up the walls, and the ramps) with box liner. Purchased as a box liner kit from a paint shop, sprayed on with the air gun it comes with. I didn't put the dye in, which was an accident. But it's fine clear, or if you dye it I recommend using white to keep the trailer bright. A black floor is really going to cut down on the light inside the trailer, and require probably twice as many lights to compensate.