This is the perfect squaring up ruler -- with 1/8" markings, it is perfect for cutting those odd-size squares that will be cut into half-squares or quarter-square triangles.
This ruler has four distinct line styles for 1/8", 1/4" 1/2" and 1" increments. Every line has spaces so you can align the cut edges of the fabric with the line, not on one or the other side of a line! The last 1/4" is clear on two sides to easily check 1/4" seam allowances.