Great Planes Building Board Modification
I have been using a piece of 3/4 pine plywood (A/C grade) 2'*4' and have had much success. I have no trouble pushing pins into it (you can always use a pin pusher). Home depot sells them already cut to this size. Since I am no longer allowed to use the kitchen table. I have built a small work room in my basement. I will be making a work table using a piece of 3/4 inch birch ply with a sub frame of two rails (front and back) made from two pieces of 3/4 ply laminated together(this will be a very rigid header). The pieces will be ten inches in width and cut on a table saw so they will be true. I will then put the same size (10" rips of ply) between the rails every sixteen inches. Sort of like the framing of the floor in a house. Since all the pieces will be the same width and cut on a table saw, as long as you are accurate when you assemble you will have a very flat frame to lay the table top on. If you feel that it will be too hard to push pins into the ply you can always lay ceiling tiles or other softer material on top. I tried the birch and to my surprise I was able to push pins into it. The only thing left to do is to support it with some legs. My table will be 4'*8' and the back will be supported by attaching the back rail to the wall and the front rail will have legs.
James