How fabric is dyed and why the colour stays
Short answer: The dye bonds to the fibre in a warm bath, and this bond decides whether the colour lasts over time. Excess dye that has not bonded to the fibre washes out in the first few washes, which is why new clothing often bleeds a little at first.
The dye has to bond chemically
A dye that only sits loosely on the fibre surface washes out quickly. For the colour to last, it has to bond chemically to the fibre structure itself, which requires the right combination of temperature, time and chemicals in the bath.
Excess dye is rinsed out after dyeing
After the actual dyeing, a thorough rinse follows to remove dye that has not bonded. The more thorough the rinse, the less the new item bleeds when it is washed at home for the first time.
Dark colours use the most dye
Reaching a dark shade requires noticeably more dye than a light one. That means there is also more excess dye to rinse out after a dark dyeing, which explains why dark clothing bleeds the most at first.
Yarn dyeing versus piece dyeing
If the yarn is dyed before knitting, the colour penetrates each thread evenly from every side. If the finished fabric is dyed instead, the colour can sit slightly differently depending on how dense the weave or knit is at that spot.
Bamboo viscose takes up dye easily
See bamboo t shirt for women for an example of a fibre that takes up colour evenly, because the cellulose in viscose has a good affinity for many types of dye compared with certain synthetic fibres.
Elastane is dyed differently
Elastane in a knitted blend usually needs a different dye than the viscose itself. See bamboo underwear for women, where the blend is treated in several steps so both fibre types end up the same shade.
How to reduce bleeding at home
Wash new, dark clothing on its own for the first few times, preferably at a slightly lower temperature. That protects other clothing from any bleeding while the last trace of excess dye gradually disappears from the fabric over time.
Lightfastness is different from wash fastness
A colour can hold up well in the wash but fade in sunlight, or the other way around. The two properties are tested separately, and a good colour should ideally hold up well in both areas over time.
Our range
See our whole range of bamboo clothing for women, where the colours are chosen so they both hold up well in the wash and work well together across the different styles in the collection. See also bamboo tops for women for more colours in the same quality.
Frequently asked questions
Why does new clothing bleed colour?
Because excess dye that has not bonded to the fibre washes out in the first few washes. The more dye that was used, the more there can be left to rinse out.
Why does dark clothing bleed the most?
Because dark colours need noticeably more dye than light ones. That leaves more excess dye to rinse out once the actual dyeing process at the factory is finished.
What is the difference between yarn dyeing and piece dyeing?
With yarn dyeing, the yarn is dyed before knitting or weaving. That often gives a more even colour than when the finished fabric is dyed all at once afterwards in a large bath.
You can find the full range at Bamboo-Clothing.com.
