I love this ruler. It is a tool that helps make perfect half-square and quarter-square triangles. The ruler is marketed by the June Taylor company, and no, I am not being paid for this endorsement. I love simple tools that make a quilter’s job easier. If you have ever tried making dozens of quarter-square triangles from paper templates, you have experienced some serious frustration.
The ruler helps accomplish the three steps required to make the half/quarter-square: cutting an accurate square of fabric, marking an accurate center seam, and cutting accurately to achieve the finished half/quarter square.
Placing two fabrics, right sides together, you use the ruler grid which has guides every half inch for your rotary cutter blade to accurately cut two squares simultaneously. Using the seam guide, you place the ruler
down the center of the blocks (shown in the photo on the top left) and mark a sewing line. Sew along the marked line. Using the cutting guide (shown in the photo on the top right), cut apart the two half-squares. Place the two half-squares right sides together and repeat this process (which is depicted in the above photos) to create perfect quarter-square triangles. The ruler grid lines can then be used to square up the blocks. Voila! Perfect half and quarter-square triangles every time.