Last week, a couple people asked me how I made my own blocking board. Actually, my dad made it, I just helped a little bit.
MATERIALS: Plywood, foam, adhesive spray, fabric, staple gun.
First, buy a piece of plywood. The plywood you chose should be sturdy without necessarily being heavy.
If you have access to a table saw, cut the plywood to 3 feet square. If you don't have access to a table saw (I don't) some lumber yards will cut the wood to size for an extra charge.
Visit your local upholstery store and buy a sheet of 1-inch thick foam that also measures 3 feet square. You might have to join two pieces together to achieve this size. The upholstery store should sell a special spray adhesive that works with foam. (Some adhesives can cause the foam to disintegrate, so be careful.) You can use the adhesive to join the foam pieces, and to attach the foam to the plywood.
[I don't need to remind anyone to use the spray in a well-ventilated area, do I?]
Next, buy some heavy-duty fabric. A couple yards of 60-inch wide fabric should be plenty to cover your board. For my board, I found some heavy-weight upholstery fabric that was printed with a grid. Of course, you don't need to have a grid, but it makes laying out your pieces easier. Wash and dry the material to remove any loose dye, and (if necessary) iron it.
Closeouts and remnants can be great sources of inexpensive fabric (I bought my material for $1 a yard.) For a list of fabric stores in downtown Boston, click here.
Attach the foam to the plywood, using the adhesive spray. Let the adhesive set (Read the instructions for your particular brand of spray to determine the correct drying time.)
Lay out your fabric on a flat surface, right side down. Place the foam-covered surface of the plywood on top of the fabric (so that the foam is facing down). Wrap the ends of the fabric over to the non-foam side of the plywood and staple the fabric to the board. You might need another person to give you a hand with the fabric. One person can hold the fabric taught, and the other person can staple. Leave only about an inch between staples, so that the fabric's tension is consistent.
That's all there is to it! The only drawback of this blocking board is that it doesn't fold smaller for storage, like some store-bought boards can do.