A great flashy fiber from Textreme in a really beautiful range of colors. Use in streamer wings or as ribbing and bodies on all your favorite flies. A ton of great colors for Perdigon bodies especially, the Flash Black in particular makes a wonderful material for Devin's Diabaetis nymph.
Textreme is one of the most experienced textile companies in Italy, and their fly-tying range shows the incredibly superior experience they have compared to many manufacturers. They make all their own raw materials with the strictest quality control, and then have world-class dye houses do the coloring of the product using a precise digitally-controlled dying process that results in absolute consistency across batches, meaning the spool or hank of material you buy today will be the exact same shade as the one you buy 6 months from now. This level of consistency is a god-send for American tiers who have dealt with constantly varying dye lots and quality for decades now.