STRIP 1 (make 2)
With A, chain 15.
Row 1: Half double crochet in 3rd chain from hook and each chain across - 13 stitches.
Row 2: Chain 2, turn, half double crochet in each half double crochet across.
Rows 3-11: Repeat Row 2.
Change to B by fastening off A, then joining B with a slip stitch in first stitch of next row and repeat Row 2 for a total of 11 rows.
Change to A and repeat Row 2 a total of 11 times.
Change to B and repeat Row 2 a total of 11 times.
Repeat last 22 rows once more.
STRIP 2 (make 2)
With B, chain 15. Work as for Strip 1, but working first 11 rows with B, then 11 rows with A, 11 rows with B, 11 rows with A, 11 rows with B, and 11 rows with A. Fasten off.
Beginning with Strip 1 and alternating between Strips 1 and 2, sew Strips together along long edges. Weave in ends.