1. Use a quilter's pencil to mark a diagonal line on wrong side of each pink print 2-3/8-inch square. (To prevent fabric from stretching as you draw lines, place 220-grit sandpaper under the squares.)
2. Layer a marked pink print 2-3/8-inch square atop each dark pink print 2-3/8-inch square. Sew each pair together with two seams, stitching 1/4 inch on each side of drawn line (Diagram 1).
3. Cut each pair apart on drawn line to make two triangle units (Diagram 2). Press each triangle unit open, pressing seam toward dark pink triangle, to make 40 triangle-squares total (Diagram 3). Each triangle-square should be 2 inches square including seam allowances.