Originally Posted by
MadQuilter
Making 8 at a time sounds like the method where the bias is on the outer edge. I do not like that method at all. Too much stretchy.
According to the PDF link above that shows how these triangles are made, the outer edges are all on the straight-of-grain. Basically the tool is a big X that allows you to quickly mark squares for sewing. You are marking the lines on the bias and sewing on the bias, so that the outer edges all remain on the straight-of-grain. The method that leaves the cut edges on the bias has you sew all around the outer edges of the squares. Quite different.