The document discusses the role of yarn in denim development. Yarn is the base for any garment quality and different types of yarn play a large role in the finished garment when it comes to denim. Open end or ring yarns between 16 Ne are commonly used for basic denim items and produce different wash effects, with ring yarn producing stronger garments. Carded yarns introduce unevenness and reduce price, while combed yarns produce regular, shiny items. High or low twist yarns change the look of garments due to differences in light reflection. Slub yarns produce various fashion effects depending on slub length and pause length.