Assemble Arc Units
To foundation-piece, stitch fabric pieces to a foundation paper with the marked side of the paper facing up and the fabric pieces layered underneath. The resulting pieced units will be mirror images of foundation papers.
1. For one arc unit, gather six matching purple or green print 5x7" rectangles and five gold print 3x7" rectangles.
2. Aligning long edges, layer a purple or green print 5x7" rectangle atop a gold print 3x7" rectangle.
3. Place an arc foundation paper atop layered purple and green rectangles, positioning it so that rectangles’ aligned edges are 1/4" beyond stitching line between positions 1 and 2 and at least 1/4" beyond arc’s top and bottom stitching lines (Diagram 1). Check placement; pin on the line between positions 1 and 2, then flip gold print rectangle open. Make sure it completely covers position 2 and extends into position 3 at least 1/4". If it doesn’t, reposition and recheck until it does.
4. Working with marked side of arc foundation paper up, sew on stitching line through all layers, extending stitching past beginning and end of the line by a few stitches (Diagram 1).
5. Press rectangles open, pressing seam toward gold print rectangle (Diagram 2). Trim gold print rectangle to about 1/4" beyond stitching line between positions 2 and 3 pieces (Diagram 3).
6. Align a matching purple or green print 5x7" rectangle with trimmed gold print piece so their right-hand edges are about 1/4" beyond stitching line between positions 2 and 3 (Diagram 4). Sew on stitching line. Trim seam allowance if needed; press seam toward purple or green print rectangle (Diagram 5). Trim just-added rectangle to about 1/4" beyond next stitching line.
7. Continue adding gold print rectangles and matching purple or green print rectangles in an alternating pattern, trimming in the same manner, until you have pieced an entire arc (Diagram 6).
8. Trim all fabric layers and foundation paper on dashed lines to make an arc unit (Diagram 7).
9. Repeat steps 1–8 to make four arc units total.