Quilt In A Day Kaleidoscope Ruler They are made of a heavy gauge plastic and are Laser Precise. A triangular ruler to cut the pieces required for the 45-degree angles in QND2009 Kaleidoscope Quilt pattern, sold separately Made of heavy gauge acrylic Laser precise marking lines in .25", .5" and 1" markings with .25" lines provided for seam allowance.