A pile of brightly coloured folded towels.

Colour Fastness Test

In general, it’s best to separate your colour washing from your white washing. But it’s worth knowing if clothes (especially new ones) are colour fast before you put them in with a regular wash. That way, you can keep their dye from running into other clothes, which can leave them looking an undesirable shade! So check the care tag before washing, and do this easy test for colour fastness.

What is colour fastness?

If a fabric is non-colour fast, the dye isn't fully fixed onto the fabric, meaning that it might fade and run into other items of clothing. The quality of dye or method of dyeing used on a fabric can affect its colour fastness, and often new items of clothing will be less colour fast than those that have been washed a few times.

A colour fast fabric is resistant to fading and running, so it is safe to be washed as usual with other items of clothing. Regardless of colour fastness, clothes should be washed with similar colours to ensure that colours are kept vibrant and whites are kept bright.

Colour fastness test for soaking or washing

Follow these steps before putting a new coloured item of clothing into the wash.

  1. Dampen a small area of hem or inside seam with water.
  2. Iron a piece of white fabric or kitchen paper onto it.
  3. If the paper soaks up any colour, your garment isn’t colour fast.

Colour fastness test for solvents

A coloured item of clothing should be tested for colour fastness before a solvent is used as a stain remover on the fabric. This includes solvents like eucalyptus oil, methylated spirits, white spirit/turpentine substitute, and nail polish remover. Do the following test before using any of these products as stain removers on the fabric.

  1. Dampen an inconspicuous part of the garment with your chosen solvent.
  2. Blot the area with a white cloth or a tissue.
  3. If any colour blots off, the garment is non-colour fast with the solvent used.

Caution: Do not use an iron to test solvents.

How to wash new or non-colour fast clothes

If you have established that an item of clothing is non-colourfast, follow these tips to prevent the dye from fading or running into other items of clothing.

  • Wash the item of clothing in cool water (30°C or under) – dye is much more likely to run in hot water temperatures.
  • Turn the item of clothing inside out to reduce the chances of fading.
  • Wash the clothing either separately or with similar colours, so that it doesn't matter too much if the colour does run a little.
  • Don’t leave damp clothes in the washing machine, as wet clothing is likely to bleed – remove and dry the laundry as soon as the wash cycle is finished.
  • Use a detergent that helps to keep colours vibrant, like Persil Colour.

Test your clothes for colour fastness and follow these tips for washing non-colour fast clothes to keep your colours vibrant.

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