I believe it is called Paperless Paper Piecing. I have used it and I like it. It work especially well if you have the add 1/4 inch ruler with the little inset. When you fold back the pattern along the line, you align the 1/4 inch ruler along the pattern edge and cut the 1/4 inch seam allowance on that last piece. This gives you the correct seam allowance to sew the next piece along.