30 Denier GSP Veevus is an ultra-strong, fine thread ideal for tying delicate fly patterns with precision. Despite its thin profile, this gel spun polyethylene (GSP) thread offers superior strength, making it perfect for tying small flies, midges, and intricate patterns. Veevus 30 Denier GSP is a must-have for fly tiers seeking durable, high-performance thread that can handle even the most demanding fly-tying applications, whether in freshwater or saltwater environments.