Abstract: The sheet material cutting system includes a cutting board having a reference corner with its two edges at a right angle with respect to each other. Cutting grooves are formed in the cutting board through the top layer thereof to expose a different colored layer for groove visibility. The grooves are positioned at known distances from the reference corner. The reference corner carries stops so that, when a sheet of colored transparent material is placed against the stops, the grooves can be used to guide a knife for cutting a square piece of colored transparent material for use in color frames in stage and similar lighting systems.