if you're asking about traditional fabrics for quilting, I'd say 100% cotton fabrics of a medium weight. Others might add that traditional fabrics whould have a certain type of print - eg, civil war, etc., but I'm not concerned about the print as much as the weight. Seersucker, silk, cordoruy, denim, etc are, to me, not traditional fabrics for quilting, but today are successfully used in quilting.