Clearview Triangle Rulers are made of 1/8 inch thick clear acrylic. The 6 inch triangle rulers can be used to produce any pattern based on 30 degree, or 120 degree angles including Tumbling Blocks, Grandmother s Flower Garden, Seven Sisters, Hollow Cube, Downtown, and more. All triangles are ruled in black. Ruled every 1/8 inch and with extra diagonal lines allow for keeping the 60 degree angle true. Laser cut for superior accuracy. 10 inch.