Toad&Co Sustainability Cheat Sheet says The textile industry is the second largest industrial polluter, second only to oil. They rate fibers based on their environmental impact.
Good: Organic Cotton, Tencel^®, Lenzing Modal^®, Recycled Polyester, bluesign^® Approved

Not so Good: Acrylic, Bamboo Viscose, Conventional Cotton, Silk

See Bedding - duvets, comforters, sheets, covers

Stores:
Organic Bedding | Bamboo Bedding | Ultimate Green Store
Bedding - duvets, comforters, sheets, covers
Budget Basics: The Best Organic Bedding Under $100 — Shopper's Guide | Apartment Therapy

Links:
Eco Friendly Mattresses