Be sure your piece of wood is 22 inches long. It should be at least 2 inches wide and 1 inch thick.
Saw the wood in half. You will use these two 11-inch pieces of wood for the "clapper" part of your clapboard. Sand the edges of the wood smooth.
Use the saw to cut a section of plywood to 11 inches-by-11 inches. The plywood should be 1 inch to 1-1/2 inches thick
Use the spatula to apply a thin layer of wood filler to one side of the plywood.
Sand the side of the plywood with the wood filler on it to make it slightly smooth. You will use this side as the "face" of the clapboard.
Set one of the 11-inch pieces of wood across the vertical edge of the plywood. Nail them together with the hammer.
Set the remaining 11-inch piece of wood on top of the other one. Fasten the metal hinge to the left edge of both, using a screwdriver.
Paint all of the pieces of wood black.
Paint a 1-inch thick, white, diagonal stripe on the bottom piece of "clapper" wood, alternating every inch with the black paint. Do the same on the top piece of "clapper" wood, making sure that the white stripes are at the opposite diagonal angle of the stripes on the bottom "clapper wood.
Paint the slate template using the white paint. The standard template includes: name of production, roll, scene, take, director, camera and date.