"Cool Wool garments are manufactured from lightweight Merino wool fabrics with a maximum weight of 190 g/m² and a maximum mean wool fibre diameter of 22.5 micron. The fabric/garment surface is clean and smooth. Cool Wool Fabrics and garments carrying the Woolmark are normally 100 per cent Pure New Wool but can include blends of wool with fine animal fibres. For fabrics and garments where wool is blended with other natural fibres (cellulosic or silk), the Cool Wool label is used in conjunction with the Woolmark Blend logo. The inclusion of elastane-type filaments to impart stretch characteristics to the fabric is permitted."