Omnigrid Right Triangle !
Omnigrid Right Triangle Rulers are made of durable acrylic plastic with both yellow and black printing which allows you to see the grid on both light and dark fabrics. There is a left and right handed numbering system and the bias lines are oriented to the bottom of the ruler. This eliminates flipping and turning of the ruler to use both sets of the diagonal lines. Omnigrid Rulers are extremely accurate. Each ruler is laser cut to within .002-inch accuracy.