A special blend of superwash machine washable Polwarth with 15% nylon. The nylon gives extra strength for sock wool.
Superwash machine washable wool is great for dyeing as it will not felt.
Nylon takes the same types of dyes as wool. This combination means it can be very easily dyed with Landscape dyes for some creative sock work.
Being superwash treated this wool is machine washable and will not felt.