Draw a line 12 inches from the open edge of the fabric the entire length of the material, 3 feet 4 inches. The fabric is 53 inches wide, but it comes folded in half or 26.5 inches. Draw marks 12 inches from the edge that opens along the length of the fabric and connect the mark to form a line 3 feet 4 inches long. The sharpie will penetrate the material and mark both layers.