Chain a length to equal desired width in multiples of three + 4
Row 1: Dc in 4th ch from hook, dc in each ch across, turn.
Rows 2-3: Ch 2 * front post (fp) in each of next 3 sts, back post (bp) in each of next 3 sts; repeat from * across to last st, dc in last st.
Rows 4-5: Ch 2 *bp in each of next 3 sts, fp in each of next 3 sts; repeat from * across.
Rows 6-: Repeat rows 2-5 consecutively. At end of last row, fasten off.