One sheet ripped down into 12" wide strips and then cut down into multiple increments of feet (1', 2', 3', 4'), stacked them & screwed them together. This created a much more consistent slope. I have the 2"x12" style that others have posted pictures of and I like the idea above better. I will me making a set for my self here soon. If I remember correctly it was made out of a single 4'x8' sheet of plywood.