6.3 oz/ly (CA), 3.8 oz/sq yd (US), 128 gsm (EU). 100% performance polyester interlock with wicking technology. No Bleed Fabric (NBF) created with a unique cationic dye process for easy printing. Side seamed. Contoured fit. Breathable. Tagless. Classic fit.   Due to the nature of polyester, special care must be taken throughout the decoration process. Please refer to product size spec PDF file for more details.