The Women's 100 Cotton Crew Socks are made with 100% Organic Cotton, with spandex to have a very comfortable sock for your normal wear, it鈥檚 breathable, durable, antibiotic and protective for your foot. Product Specification Product NameWomen's 100 Cotton Crew Socks StyleCotton Socks MaterialCotton/Polyester/Spandex ColorsAssorted in Stock/Custom Design Acceptable SizeUS 10-13/EU 43-46 TechnologyJacquard Patterned ODM/OEMWelcome ODM/OEM Orders Payment MethodL/C T/T PayPal Trade TermFOB/CFR/EXW Shipping WayBy Sea/By Air/By Express(FedEx/UPS/DHL/TNT) Sample Time5-10 Days Polyester is a man-made petroleum-based synthetic fibre. If you were to look at it under a microscope, you would see the plastic fibres are woven very finely and very close together. One of the main benefits of polyester material is its durability. It is a very strong material than others and will last much longer than cotton if cared for properly. Polyester also holds color better and longer than cotton, as well as being quick drying and non-absorbent. There are two main problems with polyester material.The first is that it鈥檚 incredibly bad for the planet as it does not break down once thrown away. It also isn鈥檛 breathable, therefore making foot sweat and overheating real problems. Cotton material is much softer than polyester and is a much better choice if you are wanting more comfort from your socks. Cotton material holds color relatively well, but there are materials that keep color better and for longer.Women's Crew Socks factory website:http://www.betopsocks.com/women-s-socks/women-s-crew-socks/