What mercerised means

Short answer: Mercerised means the yarn has been treated with a lye that makes the fibres swell and become round. The result is a stronger yarn with more shine. Here is what the treatment does, where you meet the word and what it means when you read a label.

What the word means

Mercerised is a treatment of yarn or fabric in which the fibres are placed in a lye. The word often appears on clothing labels and says something about how the yarn was made before the fabric was knitted or woven. It is a factory process that you cannot see or influence yourself.

What the treatment does

The fibres swell and straighten out, and the surface becomes smoother. Before treatment the fibre is rather flat and twisted, afterwards it is rounder. That changes the yarn in a way you can feel and see in the finished fabric, and it is the reason the treatment is used.

Why the fabric gets shine

A smoother yarn reflects light evenly across the whole surface, so the fabric gets a slight sheen. A rough surface scatters light in many directions and looks more matt. The shine is not glossy, but a calm and tidy surface, seen most in daylight. See bamboo shirt for men.

A stronger yarn

Round fibres sit closer together in the yarn, and that makes the yarn stronger. A stronger yarn copes better with being knitted, woven and washed many times. It does not mean the garment cannot wear out, but the yarn is a better starting point than if the fibres had not been treated.

Deeper colours

Colours become deeper because the fibre can take up more dye. It shows most on dark colours, which get a more even and fuller look. It also means the colour often holds better after washing. See bamboo shorts for men if you want to compare colours and surfaces.

Less lint

The treatment also gives less lint, because the short fibre ends settle into the yarn instead of sticking out. A yarn with many loose ends sheds fluff and forms small pills sooner. Less lint gives a tidier fabric over time, and that is one of the practical benefits of mercerised yarn.

Where you meet the word

Most often on cotton, less often on viscose, because viscose already has a smooth surface. If a label says mercerised, it is therefore usually a cotton product or a blend with cotton. See bamboo tops for women, where you can read the material on each item.

Can you see it on the garment

A slight shine in daylight is the sign. Hold the garment at an angle to the light and see whether the surface looks smooth and a little glossy. You cannot be sure, but the label or product description says if the yarn is treated. When in doubt, trust the text, not only your eye.

Does the effect last in the wash

Yes. It is a permanent change to the fibre, and it does not disappear in the wash. You can therefore wash the garment as normal without fearing that the shine or strength is lost. Follow the care label and the garment stays neat for as long as possible.

Frequently asked questions

Is mercerised always better?

For colour and shine, yes. For softness the difference is small. It depends on what you want from the garment and whether looks or feel matter more to you.

Can you see it on the garment?

A slight shine in daylight is the sign. You can only be sure if the label or product description mentions the treatment, so read the text before buying if it matters to you.