Where does a T-shirt’s colour come from?

Look at the T-shirt you wore today. Is it red like a strawberry, or blue like the sky? Run your fingers over it and feel how soft it is.

Shops hang T-shirts in every colour, with rows of yellow, green and purple. Let's wonder together: where does a T-shirt's colour come from?

Every T-shirt starts as plain cloth with no bright colour at all. The cloth is white or a soft cream, like fresh milk. So somebody has to add the colour.

If you looked very closely at that cloth, you would see fibres, which are tiny hairs much thinner than the hairs on your head. Each thread of the cloth is lots of fibres twisted together. These fibres are where the colour will go.

The colour comes from dye, which is a coloured powder made to soak into cloth. People called dye makers mix it in factories. They can make every colour you can think of, from lemon yellow to deep navy blue.

Next, workers at a dyeing factory stir the dye into a huge tank of hot water. Hot water helps the dye spread out evenly, so every part of the cloth gets the same colour. Soon the water looks as bright as the T-shirt will be.

Then the workers lower the white cloth into the coloured water and keep it moving. The dye slips between the threads and soaks right into each of the fibres. When the workers rinse the cloth in clean water afterwards, what do you think happens to the colour?

The clean water carries away only the extra dye that is still loose. The dye inside the fibres has joined onto them and holds on tight, so the colour stays. That is why your T-shirt keeps its colour wash after wash.

A T-shirt's colour comes from dye that dye makers mix and workers soak into the fibres of plain white cloth. The dye holds on tight inside those fibres, so the colour stays wash after wash.

So the bright colour on your T-shirt was once just dye swirling in a big tank of hot water. Now it sits snug inside every fibre, right there on you.