MFC GSP Thread

When you need maximum strength with minimum bulk, reach for Montana Fly Company GSP Thread. Built from Gel Spun Polyethylene (GSP), this premium fly tying thread delivers extremely high breaking strength and zero stretch, giving you precise tension control for everything from micro patterns to heavy-duty streamers and predator flies.

Because GSP lays flat, you get clean wraps and sleek heads without building unnecessary bulk—especially important on smaller flies where every turn of thread matters. And when you’re cranking down on hair, foam, synthetics, or tough materials, MFC GSP gives you the confidence to pull tight and lock things in for durable, fish-ready flies.

Why MFC GSP Thread Belongs on Your Bench

Ultra-High Strength

• Extremely high breaking strength for tight, secure, long-lasting flies
• Ideal for spinning deer hair, cinching down materials, and building durable patterns

Zero Stretch = Total Control

• GSP does not stretch, so your wraps stay exactly where you put them
• Delivers consistent pressure for clean, precise, repeatable tying

Flatter Wraps, Less Bulk

• Lays flat to reduce thread build-up on small flies and neat heads
• Great for sleek bodies, clean tie-ins, and crisp finishing work

Best Uses 

Montana Fly Company GSP Thread is a go-to for:

• Deer hair bugs & streamers (spinning, stacking, and compressing)
• Baitfish & predator patterns (bucktail, synthetics, articulated flies)
• Foam terrestrials and high-tension tie-ins
• Small, intricate flies where you want strength without bulk
• Big, bulky patterns where you need thread that won’t fail under pressure

Denier Options

Choose the right size for your tying style and pattern size:

• 30D – ultra-fine strength for small flies and clean heads
• 50D – versatile all-around choice for trout and light streamer work
• 100D – strong for streamers, bass bugs, and heavier materials
• 200D – maximum power for deer hair, saltwater, and predator patterns

If you’re looking for the strongest fly tying thread with flat wraps, no stretch, and serious durability, Montana Fly Company GSP Thread is the bench staple you’ll keep reaching for—whether you’re tying tiny trout flies or building big, hard-fished patterns that need to hold up.