Danville 16/0 Spiderweb Fly Tying Thread- Danville is one of the oldest fly-tying thread companies the U.S. In reference to thread size and strengths, they are used as a standard. Danville's Spiderweb thread is a 16/0 thread great for the smallest of flies (midges, baetis, micro caddis), and realistic flies, as well. Mark with Chartpak (Chartpak AD Markers) or Copic markesr to achieve the desired colors. 30 denier nylon fly tying thread is available in white only. Breaking strength is 4 ounces. 100 yard spools.