Dyeing Cellulose Yarns

Cellulose Fibres are plant-sourced fibres including Abaca paper, bamboo, cotton, Cupro, linen and Tencel.

Yarns made from mostly cellulose fibres should be dyed with natural dyes, Procion MX™ or fibre-reactive dyes.

Disclaimer: The following information is provided for you to use at your own risk. It does not constitute professional advice, and is only relevant to yarns purchased from Chester Wool Company Ltd.

Preparation

In general, our yarns are supplied ready for dyeing. Although our cellulose yarns are prepared for dyeing, they do benefit from an extra scouring step. This helps the dye penetrate better and will give you stronger colours. The procedure is the same whether you are using natural dyes, Procion MX or fibre-reactive dyes. We recommend the following steps:

1. For 1kg of yarn, add 20ml of Synthrapol and 40g of soda ash (sodium carbonate) to a pot with plenty of water.
2. Add the yarn and simmer for 1 hour.
3. Rinse and then proceed as you would normally for dyeing a cellulose fibre.

Dyeing process

The process when using fibre-reactive dyes differs from acid dyeing in that you don’t need acid or heat. Dyes for cellulose fibres rely on a higher pH (10-11) rather than a lower (acidic) one, cooler temperatures and time. Keeping the dyes around 30-40ºC does aid colour uptake.

In addition to your dyes, you will need soda ash (sodium carbonate) to increase the pH and make the yarn more alkaline. In addition, salt will be needed for good colour, preferably non-iodised, but if that’s all you have it's fine.

You may also find urea helpful. As the dyes require a longer period of time to fix, urea acts as a humectant (which means it attracts moisture). I use this if I am painting yarn with dye (method 2 below), but it’s not necessary for low-immersion dyeing (method 1 below), as the yarn will be submerged in water.

Once you are done fixing the yarn it needs to be rinsed. Don’t panic if quite a lot of colour comes out. That’s quite normal with these dyes, rinse with cool water first, and then near the end, you can increase the heat to wash the excess particles out, but don’t use hot at first as this can cause dye release over subsequent washes. You can use Synthrapol to help, or I sometimes use washing-up liquid once I’ve done an initial rinse to remove any residual sodium carbonate.

Additive Quantities

Method 1: Fluid blended colours

This method gives you good, strong, semi-solid colours and multis.

1. Add salt to warm water (see above for quantities) and stir to dissolve.
2. Add the yarn to the salt solution and soak for 15 minutes.
3. Remove the yarn and squeeze excess salt solution back into the bath.
4. Add the soda ash to the salt solution and make sure it's fully dissolved.
5. Add the yarn back in, and now add the dye solution and move yarn around so it's saturated in colour.
6. Leave in a warm place or you can use a water bath (bain-marie) for 1.5 hours.
7. Rinse.

Method 2: Controlled dye fixing

This method is used for dyeing techniques where you want the dye to fix quickly to the yarn it strikes, for example when hand-painting. The dye fixes more quickly this way, as the dye solution is more alkaline, this can result in more patchy colour, which can be exploited as you wish.

For this method, you will add the soda ash directly to the dye solution, so you don't need to scale it up per litre of water. It may not all dissolve, so you can use less than for method 1.

1. Add salt to warm water (see above for quantities) and stir to dissolve.
2. Add the yarn to the salt solution and soak for 15 minutes
3. Remove the yarn and squeeze excess salt solution back into the bath.
4. Make up your dye solution and add the soda ash directly to the dye.
5. Apply the dye to the damp yarn as you wish.
6. Leave in a warm place or you can use a water bath (bain-marie) for 1.5 hours.
7. Rinse.