A very small good thing in this case, as these are children's socks. Their Merino wool contributes to comfort and durability.
68% Merino, 17% Nylon, 12% Polyester, 3% Polyurethane. They recommend avoiding tumble dry as this may cause shrinkage.
Rototo Socks are made in Nara Prefecture which has been Japan's largest sock producing region since the 43rd year of the Meiji Era (1910), when a man there visited the United States to purchase a sock sewing machine. Woven using old-fashioned sewing machines, Rototo makes "consumables that we can love for a lifetime."
