Nylon and polyester are windproof, breathable, and downproof. They have the added bonus of being light, stuffable, and relatively inexpensive.
Denier is a measure of density of weave in threads per unit measure.
As a general rule, the higher the denier, the more durable the fabric is. Insulation and Construction Technologies. Reinforcement Fabrics Cordura Cordura nylon is legendary for its strength and abrasion resistance. When sanded, the surface feels like a very soft canvas, but it has many times the durability. This incredibly durable fabric made with Cordura and 3-ply yarns has a soft hand suitable for lighter weight applications.