UTC 140 denier has long been one of the 'standard' threads for fly tiers around the world. Unlike Uni or standard Veevus threads, UTC is a floss, allowing the tier to tie with it 'flat' yielding very slim and smooth bodies or (by spinning the bobbin) the tier can tie with it 'round', making it stronger but less smooth. This versatility, along with their expansive array of unique and vibrant colors, has long made tiers choose UTC as their preferred thread.
I don't know if it's quality control or a new supplier UTC has been using, but for the past year or so, the quality of this product has been poor. The thread is not wrapped tightly or uniformly on the spool. When tying the thread under tension starts to dig in to the the loose wraps start to unravel in your hand while tying. I rate it two stars because I'm still able to tie flies, but it's not ideal.
