Why viscose shrinks and how to avoid it

Short answer: Viscose fibres absorb a lot of water and become soft when wet. When heat and mechanical movement are added, the fabric draws together, and that is when shrinking happens. With low heat and gentle drying you can avoid most of it.

Water softens the fibre

A wet viscose fibre is weaker and more pliable than a dry one. The fibre soaks up water and swells, and in that state it draws together more easily. That is why damage happens in the wash and especially in drying. Once dry again, the fibre keeps its shape well.

Heat is the trigger

At 40 degrees almost nothing happens to bamboo clothing washed correctly. It is in the tumble dryer and at high temperatures that the fabric shrinks. The mix of heat, moisture and movement in the drum causes the most trouble, so the dryer is the first thing to avoid.

Spinning

A hard spin presses the fibres together while they are wet and weak. That can cause both shrinking and creases that are hard to remove. 800 to 1000 rpm is plenty for bamboo clothing. The clothes come out a little wetter, but they dry quickly on a rack.

Dry flat or hanging

Lay heavy pieces such as sweats and knits flat, and hang light pieces such as T-shirts and underwear. That way the fabric is not pulled out of shape while drying. Give the clothes a light shake and ease them into shape first, and you can skip the ironing too.

Do not wash too hot

Many people wash hot out of habit, but for bamboo viscose it does not give cleaner clothes, only more wear. A mild detergent at 40 degrees removes everyday dirt and odour. Skip fabric softener, because it leaves a film on the fibres, and turn clothes inside out.

If the damage is done

A shrunken piece can be stretched slightly while it is damp. Lay it on a towel, gently pull it in length and width, and let it dry flat. It rarely becomes exactly as before, but it can often help enough to make it wearable again.

Prevent it from the first wash

The first wash matters most, because new fabric reacts most to heat and movement. Wash at 40 degrees and avoid the tumble dryer from the start. That lays the ground for clothes keeping their size. All the details on washing and care are in the washing guide.

Where it shows most

Shrinking is most visible on T-shirts, which get shorter, and on bedding, where the cover suddenly no longer fits the duvet. Large items like bedding tempt you to use the dryer, but they dry well on a line or a large rack. See bamboo bedding.

In short

Viscose shrinks when wet fibres meet heat and movement. Wash at 40 degrees, spin at 800 to 1000 rpm, skip the tumble dryer and dry clothes flat or hanging. That way they keep their size, and you avoid unpleasant surprises after washing.

Frequently asked questions

Does bamboo clothing shrink at 40 degrees?

At 40 degrees almost nothing happens if the clothes air dry afterwards. It is mainly the tumble dryer and high temperatures that make viscose fibres draw together.