Sigma Pi Twill Letter Long Sleeve Tee High quality 4 inch double layer twill letters with satin stitching Lifetime guarantee on the twill letters - they will never come off. Letters are not embroidered onto the garment 100% Heavyweight Cotton. Dark Heather color is 50% cotton/50% polyester. Official Licensed Product - Royalties help support your national office Unconditional 30 day money back guarantee