A set of three pairs of basic ribbed crew socks, each pair a different hue made in organic undyed cotton. The grey color is also undyed, and it achieved using a chemical reaction by applying a technique called "mordanting" to a rare, light green cotton called "Green Cotton."  If you're wondering why they are not left green - the reason is simply that green cotton on its own has poor light fastness, and is prone to fading in sunlight. As with all RoToTo's products, they are knit with care and attention to fit. The ribbed, crew height cuff features a 1x1 rib knit to keep the socks up where they belong, and from the heel down they are knit in a jersey knit (similar to a tee shirt) to keep them from dragging down while being worn in leather shoes. Made in Japan.