Twill material is the same type of material that the Greek letters are made from. Twill numbers are $3.50 per number per color. Numbers are 8 inches. If you would like 10 inch numbers, please contact the store. PLEASE specify what numbers are being placed on garment in the box above. Please adjust quantity accordingly so that it does not hold up your order. Selecting this feature will add 2-3 business days to the production time of your order.