These are 100% merino wool and very comfortable to wear against the skin. I bought these XL Kid Smartwool leggings for myself because they are 60% of the cost of the adult size ($60 for kids, $100 for women). I have a pair of Smartwool adult Women's size S and they are pretty snug in the waistband. The XL Kid waist is more comfortable & not as wide. I am an adult woman, albeit a short one (5 foot 1 inch on a good day). The XL Kid would probably be perfect if I were 5 feet or shorter. Compared to the Women's Small, the Child XL is a bit shorter - I have to wear slightly longer socks. I love Smartwool leggings for skiing, walking in the snow, and lounging around. I have washed them in gentle cycle and air dried - no need to dry clean or hand wash.