Assemble Block A
1. Sew together a black dot 1-1⁄2x42" strip and a black dotted line print 1-1⁄2x42" strip to make a strip set. Press seams toward black dotted line print strip. Repeat to make four strip sets. Cut strip sets into four 12-1⁄2"-wide segments and four 20-1⁄2"-wide segments (Diagram 1).
2. Add 12-1⁄2"-wide segments to short edges of a T-shirt 12-1⁄2x16-1⁄2" rectangle. Press seams toward pieced segments (Diagram 2). Join 20-1⁄2"-wide segments to remaining edges to make Block A. Press seams toward pieced segments. Block A should be 16-1⁄2x20-1⁄2" including seam allowances. Repeat to make a second Block A, reversing which black print is next to T-shirt rectangle.