Marti Michell Kaleido Ruler Large
Use this large ruler for cutting triangles for 6- to 16-inch blocks. One tool for cutting both triangles for Kaleidoscope-type blocks the easy, accurate way.
How to Use the Kaleido-RulersUse the small Kaleido-Ruler to make 2" to 8" blocks, and the large Kaleido-Ruler to make 6" to 16" blocks:
1.Pick a finished block size. Find it on the blunted 45° end of the Kaleido-Ruler and cut strips the width printed on the ruler. Then use the Kaleido-Ruler to rotary-cut the isosceles triangles for the interior.

2.To cut the corner triangle strips: On the longest side of the Kaleido-Ruler, align the desired finished block size with the evenly cut edge of fabric and cut strips that width

3.To cut the corner triangles: Turn the ruler and align the finished block size with the edge of the strip. The point should touch the opposite edge of the strip.