UNI-Cord (7/0, 8/0 and 12/0) is an extremely strong ( for the same diameter it is twice as strong as Kevlar) fly-tying thread manufactured of continuous fibers of gel-spun polyethylene (GSP). It is considerably more expensive than other threads and so is reserved for unusual situations where a fine but very strong thread is required. UNI-Cord comes on 50-yard spools and in seven colours: Black, Bright Green, Fluo.Green, Olive, Red, Yellow and White. It is also available in combo pack of 20 spools You asked for the return of UNI-Cord 12/0, 50 denier to our lineup ? I am happy to announce it is now available. The UNI-Cord 12/0 comes in six colors (Black, White, Red, Yellow, Olive and Fluorescent Green) and is available as part of a 20-spool Combo Pack which includes spools of 7/0 and 8/0 UNI-Cord. The UNI-Cord 12/0 is a top choice of tiers looking for a combination of small size and great strength. At 50 denier and a breaking-strength of four (4) pounds, it will handle the toughest jobs. For example, when dubbed with the split-thread method, it creates almost indestructible bodies.