Krystal flash is an amazingly versatile flashy fiber material that has been around for a long time and continues to earn our respect day after day, year after year. We use Krystal flash for the sole material as wing on a steelhead or salmon fly. We use Krystal flash as a topping, anywhere from two skimpy strands to a dozen strands (favorite is 6 strands) as a topping on wet flies for salmon and steelhead.