Well, I didn't ask for organic cotton. I just wrote that I want to use biodegradable materials and that they should be fair trade as well. Wool is fine. (there is also organic wool yarns) But I can't find sewing yarns.
Remember Julia to make one cotton shirt takes 3000 litres of water and adds 1200 litres of carbon dioxide to the atmosphere. Its not as eco-friendly as people think, organic or otherwise. Have you considered wool?