UNI Products J.G. Côté inc. | 6/0 UNI-Thread, 136 denier, 25 colors.
Units of textile measurement - Wikipedia
Using Denier to Standardize Fly Tying Thread | Global FlyFisher | It makes sense to have a standardization, which would eliminate much of the confusion that surrounds fly tying thread today.
Ought converted to Denier | The North American Fly Fishing Forum - sponsored by Thomas Turner
UNI-Nylon Tying Thread, 70 Denier
WAPSI UTC ULTRA THREAD 70 DENIER - FLY TYING THREAD * 2022 Stocks * UTC 70 | eBay