The soles of the soft are made from too soft material. It rubs off.
Thank you for your feedback on the Arpenaz 100 Low Top hiking sock. I am sorry to here you have had a bad experience with the product. All our socks are laboratory- and field-tested to validate the following: toxicology, UV resistance, resistance to wear, accelerated ageing and resistance to repeated washing.
Please feel free to return the product to your local store where they can offer you a full refund or exchange.
I have included a link below for a different pair of socks which will be more resistant due to the composition of the fabric. This may be more suitable to your need.
Isaac Gregg - Quechua UK Product Expert