Features of Smartwool Women's Merino 150 Plant-Based Dye Baselayer SS Top Smartwool's lightweight Merino jersey fabric Uses a nylon core to increase durability while still keeping 100% Merino wool next to skin Garments Are coloured using an environmentally conscious plant based- dye process Raglan sleeve design eliminates need for shoulder seams Side seams wrap to front for enhanced Fit Stretch merrow stitching designed to elevate comfort, range of motion, and Fit UPF 20+ Fabric Details 88% Merino Wool, 12% Nylon. Exclusive Of Decoration. 88% Merino Wool, 12% Nylon. Exclusive Of Decoration.