Fold the sheet in half lengthwise to make the fabric double in thickness and half as wide as it was originally. Sew around the perimeter of the sheet.
Fold and press a four-inch hem on both short ends of the sheet. Pin the hem in place.
Sew across the bottom of the hem, leaving the two sides open to form a casing for the rope. Go over the hem eight times to create a very strong seam.
Cut the rope into two five-foot lengths. Feed each length through the casings.
Tie the rope around the supports you are using, such as two trees or deck support posts.