The most popular quilting ruler. The 6 1/2 Triangle Square Up Ruler makes perfect half triangle squares and quarter triangle squares in sizes up to 6 1/2 inch. Fully illustrated and detailed instructions are included. The ruler is marked in two colors for easy reading. Convenient 1/8 inch, 1/4 inch, 1/2 inch and 1 inch lines for precise measuring. The Ruler is made of heavy gauge acrylic and is laser precise.