Rainy's Fly Tying Cross-Link Sheet Foam is a very durable and condensed closed-cell foam that works great for foam patterns.
Tying Sheet Foam – Fly Fish Food
Learn How to Tie the Weedless Mouse
Foam Fly Tying Materials – Dakota Angler & Outfitter
Rainy's Fly Tying Red Ant Bodies
Foam Fly Tying Materials – Dakota Angler & Outfitter
Rainy's Evazote Foam Sheets - Frontier Fly Fishing
East Walker River Fly Patterns
RAINY'S Cross Link Sheet Foam
Rainy's Fly Tying Gray Mouse Bodies
Foam – Rocky Mountain Fly Shop
Foam – Rocky Mountain Fly Shop
Willow Grubs - follow-up article, The Tying Bench