Agree with Papermoon.  For instance I put the material as cotton viscose linen polyester wool etc and the Fabric type as things like Jersey, denim, satin, georgette, etc.  

So for instance polyester can be made into all sorts of fabric, and a fabric like jersey can be made from polyester spandex, viscose, rayon, cotton etc. Satin can be silk or polyester, denim may or may not contain elastane, etc.