Mesh is a very poor choice as it tends to "grab" the spinnaker and make it significantly harder to hoist and retrieve due to the added friction. The nylon and the mesh both tend to give which is why the firmer, smoother mylars are favored. They have much less friction but little abrasion resistance and poor UV resistance. The best material I have found is balloon cloth as it is relatively stiff, has very good abrasion resistance, has excellent UV resistance and comes in a variety of colors and usually cost less.