Single vs Double / Two Ply

Typically, dress fabrics can either be Single ply or Double / Two ply. Ply refers to the number of yarns that are twisted together to make a single thread.

Two-ply fabrics are generally superior to single-ply fabrics. They have a smooth, crisp hand feel and are luxurious to wear. This is not to say that Single-ply fabrics are not luxurious – higher count single ply fabrics with compact construction are equally sought after.

The 2 in a 100/2's or the 1 in the 70/1 refer to the ply of the fabric.