A central wooden wedge holds the two blades in place. He also added a small guide marker that let’s you cut precise straight grooves. [ftregan] built the tool to allow cutting 6mm thick foam ...

In the first step, measure and cut the foam with a serrated or electric knife. The standard size of a wedge pillow is between 20 and 25 inches wide, 20 and 25 inches long, and 6 and 12 inches high.