Although Nylon was discovered and originally patented by Dupont’s Wallace Carothers, it was produced (as Nylon 6) three years later (in 1938) using a different methodology by German research chemist Paul Schlack, then working at IG Farban. In the modern era it is manufactured by a large number of firms, each typically with their own production process, unique formula, and trade names.
Common variants include Nylon 6, Nylon 6/6, Nylon 66, and Nylon 6/66. The numbers indicate the number of carbon atoms between acid and amine groups. Single digits (like “6”) indicate that the material is devised from a single monomer in combination with itself (i.e. the molecule as a whole is a homopolymer). Two digits (like “66”) indicate that the material is devised from multiple monomers in combination with each other (comonomers). The slash indicates that the material is made up of different comonomer groups in combination with each other (i.e. it is a copolymer).