In order to make a non-overlapping jib as big as possible, leech battens are needed. Without battens, the leech of the jib would curl if the sail was not cut with leech-hollow (a concave profile). By adding battens, the leech of the sail can be straight from the head to the clew, or even with some positive roach. Horizontal battens are the most efficient way to support the leech of a jib or mainsail since they are directly in line with the forces trying to make the leech curl forward. The problem with horizontal battens in a cruising jib is that standard fiberglass battens cannot be rolled up. Batten manufacturers are coming up with creative ways to make horizontal battens that roll, but they have not been perfected yet.