Permanent waterproof coating on flies, materials, dubbing, yarns, nylon leaders, braided loops and fly lines. It does not affect color or softness of material nor does it leave oil rings of any kind on the water surface. The floatability of your fly is not affected in any way by fish or weed slime. Water Shed is a pre-fishing treatment and must be applied at least 24 hours prior to fishing. Do not apply over wet material or Water Shed will not cure and waterproof properly.