Pilling occurs when loose fibres entangle during wear, washing or dry cleaning and form “pills” or balls on the surface of a fabric. These fibres bundle together and drive out from the fabric, but are still anchored by the fibres that haven’t broken away from the weave.
Pilling will occur to some degree in most fabrics, with wool and synthetics such as polyester and nylon, renown for pilling the most. Fabrics constructed from longer fibres will pill less than those with shorter fibres. The quality of the fabric’s manufacture and how it is worn and used by the individual will also impact how much that it pills.