Why twist in the yarn decides softness

Short answer: Twist is the number of turns per metre of yarn. Few turns give a soft and airy fabric, many give a firmer and more hard-wearing one. It is one of the few things the maker can adjust without changing fibre, and it affects how the clothes feel against the skin.

What twist is

When fibres are twisted around one another, they hold together by friction. The number of turns per metre is called twist, and it is one of the few dials you can turn without changing fibre. The same fibre can therefore give very different fabrics, depending on how much the thread is twisted.

Why fibres must be twisted

Viscose fibres are short and have no strength before they are twisted together. The twist presses them against one another so they do not slide apart when the thread is pulled through the machine. Without twist there would be no thread, only a loose pile of fibres that could not be knitted.

Soft versus strong

Low twist lets the fibres lie loosely, so the thread feels full and soft against the skin. High twist presses the fibres together into a hard, smooth thread that stands up better to wear. See Egtved if you want to look at more everyday clothing and feel the difference between fabrics.

What you can feel

A thread with low twist gives a fabric that feels airy and almost full. High twist gives a firmer and slightly cooler handle that lies closer. The difference is easiest to feel if you take two garments in your hand and lightly rub the surface with your fingers, one at a time.

What the maker chooses

For underwear and T-shirts, low to medium twist is typically chosen, because comfort weighs heaviest. For socks and edges, higher twist is chosen, where hard wear matters most. The choice therefore depends on where on the body the clothing sits and how much wear it must withstand in daily life.

When softness costs lifespan

There is a limit to how loosely a thread can be twisted before it loses strength. A very soft fabric can therefore wear out faster than a firmer one. It is a balance between comfort and lifespan, and the maker looks for the balance that suits each type of clothing.

Why some T-shirts feel hard at first

New T-shirts can feel a little stiff if the yarn has high twist. The fibres sit tight, and the fabric has not yet had a chance to loosen. After a few washes the surface softens, and the T-shirt feels more comfortable. See bamboo t-shirts for men and bamboo underpants for men.

What washing does to the feel

Washing does not change the twist in the yarn, but it lifts the fibres, so the fabric feels softer than when new. Follow the care label in the garment so you do not strain the fabric more than necessary. With gentle washing the surface stays comfortable, and the yarn keeps its shape longer.

Frequently asked questions

Can a soft fabric also be strong?

To some extent. There is a limit where softness costs lifespan, so a very soft fabric often wears out faster than a firmer fabric made from the same fibre.