Streamline rigging wires. I have read that photoetch RAF type wires can contract and expand, due to temperature changes, leading to problems. Flat elastic does not add any strength to the wing structure like nylon monofilament. Could flat nylon monofilament be created by passing regular round monofilament through a cranked jewelry rolling mill at near zero clearance? Too expensive to purchase one these but maybe a jeweler would let you use his for a few minutes.