To evaluate the pilling tendency in accordance with SN EN ISO 12’945-2 a photo standard can be used. Such photo standards have been developed by the EMPA in St. Gallen, Switzerland. The complete set consists of 6 series (3 for woven and 3 for knitted fabrics). Each photo standard consists of a series of 4 comparable photographs. Each comparable photograph shows the boundary between 2 marks (mark 4–5, 3–4, 2–3, 1–2). The surface condition of each test sample is judged against a photo standard, it can then be decided if the test sample is better, equal, or worse than the photo standard, resulting in a pilling mark.
Mark 5 = no or very little pilling
Mark 4 = light pilling formation
Mark 3 = moderate pilling formation
Mark 2 = distinct pilling formation
Mark 1 = strong pilling formation
(Half marks are allowed)
Each photograph is fixed to a nonreflecting plastic disc and is protected by a slightly raised rim.