What it is Fire Fly Tye is a flash material made as bonded metallic nylon strands. It has a reflective sheen with a vibrant look, and it stays strong and durable when you wrap, tie in, or layer it. What to tie with it Use it anywhere you want controlled flash in the profile: as an underwing or overwing in streamers, as a lateral line or accent in baitfish patterns, or as short hotspots in nymphs. It also works well blended into other synthetics, palmered as a flashy body, or tied in as a few sparse strands so you get sparkle without bulk. It fits both freshwater and saltwater tying, from trout nymphs to bigger predator streamers. Flies and the fish they're for Fire Fly Tye shows up in Firefly-style foam-body flies, including the Firefly 2.0, where the flash is part of that reaction, plug-like baitfish look; those are commonly fished for aggressive predators that will chase a moving streamer in rivers and lakes. The Firefly pattern is also tied and fished for sea trout, often as a dropper fly ahead of shrimp-style flies in coastal water where sea trout feed on small bait. In trout nymphs, a few strands give you the kind of attractor flash that can help get attention in faster runs and deeper pockets.