What is Pilling?

Pilling is the formation of small balls of tangled fibers on a fabric surface. The balls, called pills, cling to the fabric by one or more fibers. They form with wear, washing and drying, spoil the fabric's look and are measured with the ISO 12945 series. This entry covers textile pilling only, not skincare or makeup.

Pilling, fuzzing and matting

The title of ISO 12945 names three phenomena: pilling, fuzzing and matting. Part 4 of the standard describes assessing each of them visually and separately (ISO). In this entry fuzzing means loose fiber ends rising to the surface; it is the first step of pill formation, and a pill forms when these fibers tangle and ball up (Kahraman, 2006). Turkish suppliers use boncuklanma for pilling, but tüylenme (literally fuzzing) is sometimes used for pilling too, so name the defect “pilling (boncuklanma)” in a quotation or specification to avoid confusion.

How does pilling form?

Kahraman (2006, pp. 4–6) describes pill formation in four stages:

1. Fuzz formation: fiber ends are freed at the yarn surface; this is the first effect of abrasion.
2. Entanglement: once the fuzz reaches a critical height that depends on the fiber's properties, the fibers tangle with each other.
3. Growth: the pill grows up to a limit.
4. Wear-off: if outside forces exceed the combined strength of the fibers anchoring the pill, the pill separates from the fabric.

Whether a pill stays on the fabric depends on the strength of the anchoring fibers. With fibers of low breaking strength and bending resistance (wool and some synthetics) pills leave the surface easily, while with strong synthetic fibers they stay attached (Kahraman, 2006, pp. 4–5).

Why does it happen, and which fabrics pill most?

Kahraman (2006) gathers fiber, yarn, fabric and finishing factors in a literature review; the tendencies below come from the studies reported in that review:

How is a pilling test read?

ISO 12945 has four parts: Part 1 is the pilling box, Part 2 the modified Martindale, Part 3 random tumble and Part 4 visual assessment (ISO). Part 3 does not apply to fabrics that cannot tumble freely. The visual grade has five steps: Hossain et al. (2021) report the ISO 12945-1 scale as 1 = severe pilling and 5 = no change.

The direction of the scale is not the same in every method. Kahraman (2006, p. 17) gives the scale for the Du Pont random tumble apparatus with 1 as “no pilling” and 5 as “very heavy pilling”, and a biopolishing study used a panel index from 0 (none) to 5 (severe) (Thiyagarajan and Hari, 2014). Always confirm in which direction the grade in a report reads. For how the methods are run, see the fabric testing standards guide.

How can pilling be reduced?

1. Singeing and heat setting: on polyester-cotton blended fleece, untreated fabric scored grade 1, heat setting alone 2, singeing alone 3 and the two together 4 (ISO 12945-1:2000, 14,400 revolutions; Hossain et al., 2021). The same order appeared in three different blends; it is still one study.
2. Biopolishing (cotton): cellulase enzyme partly breaks down the fiber ends sticking out of the surface. On a cotton fabric knitted from 20s carded yarn, enzyme washing significantly lowered the pilling index given by a panel (Thiyagarajan and Hari, 2014). Cellulase breaks down cellulose, so the method suits cellulosic fibers.
3. “Anti-pilling” claims: the ISO 12945 records reviewed for this entry contain no definition of the term; have the claim backed by a grade measured to ISO 12945.

How to specify pilling in an order

1. State the method: ISO 12945-1, -2 or -3. Test devices respond differently to different factors (Kahraman, 2006, pp. 20–21).
2. Fix the revolutions or the duration: the number and size of pills change with the test time (Kahraman, 2006, p. 21).
3. Write the acceptance grade together with the direction of the scale.
4. Ask for a measurement after washing too: in a study reported by Kahraman (2006, p. 27), the tendency to pill rose as the number of washes increased.

Frequently asked questions

What does pilling mean in fabric?

Pilling is the formation of small balls of tangled fiber on the surface of a fabric. In the title of ISO 12945 it is named together with fuzzing (fiber ends rising to the surface) and matting.

What causes pilling?

Friction in wear, washing and drying frees fiber ends at the surface, and these tangle into balls. Strong synthetic fibers, fiber blends, fuzzy yarns and knitted structures make pills more likely to form and to stay (Kahraman, 2006).

What does anti-pilling mean?

It is the name given to fiber, yarn or finishing solutions meant to reduce pilling; the ISO 12945 records reviewed contain no definition of it. Ask for the claim as a grade measured to ISO 12945.

What is a pilling test?

It is a laboratory test of a fabric's tendency to form pills. ISO 12945 treats it together with fuzzing and matting: the specimen is abraded under standard conditions, the surface is graded visually, and the result is reported as a grade, not as a number of rubs. The fabric testing standards guide explains the steps.