Assemble the Block
When pinning curved seams, use slender pins and pick up only a few threads at each position.
1. With a muslin B piece on top and right sides together, match the center mark on the curved edge of the B piece with the center mark on one curved edge of the solid red A piece (Diagram 1). After pinning the center of the seam, pin each end; then pin generously in between (Diagram 2).
2. Sew together the pieces, removing each pin just before the needle reaches it. Press the seam allowance toward the solid red piece.
3. Add the remaining muslin B pieces to the solid red A piece in the same manner to make a block (Block Assembly Diagram).