Betsey, I used the 4 1/2” equilateral triangle. You will need to buy more fabric than the pattern indicates. Even hand cutting the triangles would require absolutely perfectly sized fat quarters, and that doesn’t happen. I would get 1/3 yard of each of the fabrics she says 1/4 yard is enough, though 1/2 yard will relieve your mind some. And you can alternate the position of the triangle die by leaving enough space to turn the folded layers over and cut again.