Row 1: Sc in 2nd ch from hook and in each ch across - 137 sc at the end of this row.
Row 2: Ch 1, turn, working in back loops only, sc in each st across.
Repeat Row 2 until piece measures about 38 in. (96.5 cm) from beginning.
Fold piece in half to measure 21 x 38 in. (53.5 x 96.5 cm). Place markers on each of the 21 in. (53.5 cm) sides, 7 in. (18 cm) below fold for armholes. Seam sides from armhole marker to lower edge.
Weave in ends.