I use ceiling tiles from Menards Hardware as they will sell them one at a time for about 2 dollars each or so. I use the tile with the tan fiber construction backing and use the back side on my work bench. Years ago I built two wooden work benches each 4x8 feet to construct full scale airplanes on. I just lay the tile on the bench and have at it. For larger wings I use 1/2 inch drywall. Pins are a bit of a challenge in drywall, but they hold well and it is not an expensive base.