KnowHOW team explains: Pilling, or the tendency of fibres to roll up, is a simple physical process. It can happen with any fibre as it rubs against surfaces, collecting pieces of lint, dust, dirt or oil. These roll up in the fibres and form little balls. If the fibre is weak the balls fall off, but if the fibre is strong, they hang on as ugly pills.

Unlike shrinking, which affects mostly natural fibres whose long molecules are trying to return to their original crinkled state, pilling can affect both natural or artificial fibres, depending on their strength. Because polyester is a very strong synthetic fibre, clothing with some polyester content is a candidate for pilling.

Pilling tendencies also depend on how tightly twisted the yarn in the fabric is. If it is tightly twisted, like that in a worsted wool suit, it tends not to pill as much, but if it is looser and fluffier, like the yarn in a sweater, with the ends of the fibres sticking out, it collects more material and forms more pills. Persistent pilling is the result of a high percentage of short fibres combined with a loosely knit fabric. Lower quality manufacturers use shorter fibre because it is cheaper.

To remove any pills on fabric, pull the fabric taut over a curved surface and carefully cut off the pill with scissors or shave the fabric surface with a safety razor. There are also battery-operated pill-removers, which shave the pills much like an electric razor.

The question was sent by Aniket Sen from Kharagpur