I am making a DWR according to Mary Henderson and Anne Dease, where you make the arcs and then applique them to a 12 1/2 in square. When all are assembled you piece them together and there is no curved piece sewing. I made my own arcs on lightweight interfacing and appliqued them with very narrow zigzag and clear thread. I trimmed the fabric and interfacing from the back to make it more lightweight. I used scraps from another quilt but had to buy more fabric for the cornerstones of each block. Will post a picture if I can.