Superwash is a treatment method that is used to make wool fibres more resistant to shrinking and felting. There are a different methods used to achieve this, and the methods vary in terms of durability and environmental impact. These yarns often take dye very well, and tend to have a lot more drape and stretch than non-superwash yarns. A hand-dyed yarn may be superwash yet still recommend hand washing: this is to extend the colourfastness.

Merino sheep create a wool with a long, smooth fibre that is lightweight, warm, and soft. Like all wool, it has excellent breathability and does an excellent job regulating temperature in garments. It is a very popular type of wool to use for hand knitting yarn, and is a great choice for socks and garments worn close to the skin.