Using Procion MX Dyes on Wool

Although Acid dyes are usually recommended for protein fibres, you can also use Procion MX fibre reactive dyes (here is the fibre reactive dye recipe for cellulose fibres). Even old dyes continue to work well on wool. Some of the colours will dye more true to type than others. In particular some blues produce unexpected results. These directions are based on dyeing 500g of fibre. Always test samples before working on a large project.

  • Wear rubber gloves and an apron or old clothes.
  • Utensils used for dyeing should not be used for food preparation.
  • Always read the directions carefully before starting

Undyed Merino Wool

You will need:

  • Procion MX Dye
  • Synthrapol
  • Vinegar (or Citric Acid Crystals)
  • Glauber’s Salts (sodium sulphate)
  • 10ml Syringe for accurate measures of small quantities of liquid
  • Wool for dyeing


  1. Wet the wool, using 10 litres of warm (40°C) water, to 500g of wool. Add 2ml of Synthrapol to ensure complete wetting and removal of any oils or starches. Soak for 30 minutes. Squeeze out the excess water before adding the wool to the dye bath.
  2. Make up the dye stock. Measure the dye quantity you require, in to a 250ml measure. The amounts required range from 1g for pale colours to a maximum of 10g for dark colours. Black requires 25g of dye powder. First make a paste of the dye powder by slowly adding 50ml of water at 20 to 30°C, until there are no lumps. Add a further 250ml of water; stir thoroughly and set aside.
  3. Make up the dye bath in a stainless steel or enamel pot. For 500g of wool, measure 10 litres of water at 20 to 30°C and add the following, stirring after each item:
    • 2ml Synthrapol
    • 330ml (ideally white, but brown works just as well without any staining) vinegar
    • 25g Sodium Glauber’s Salts
    • The dye stock
  4. Add the damp wool to the dye bath. Bring the dye bath to a boil gradually over a 45 minute period. Hold at simmering for a minimum of 30 minutes for pale shades and up to 60 minutes for black and dark shades.
  5. Allow the fibre to cool to room temperature in the dye bath. Rinse well in warm water.


There is no substantiated evidence of a causal link between exposure to Procion MX dyes and any chronic or fatal illnesses. Both the acid and fibre reactive dye families have a considerable track record, of use in industry in considerable quantities and in a less well controlled environment in the crafts. However, sensible precautions should be taken when handling dyes and chemicals, particularly as powders:

  • Avoid inhaling dusts, they can produce an asthma type reaction. People with known respiratory problems should not handle synthetic dyes, and particularly the fibre reactive dyes, in powder form. A dust mask should be worn when working with the powders or exposed to an aerosol from spraying dye solutions made up in water
  • Avoid splashing solutions into the eyes, swallowing the materials or prolonged skin contact. A simple ‘non-contact’ approach (most people use gloves to avoid dyeing themselves) plus normal, good, hygiene is sufficient precautions for the occasional user
  • Store in clearly labelled containers well away from children, pets and foodstuffs. Treat dye powders and solutions with the same caution as domestic poisons (e.g. strong cleaners, bleaches or medicines)
  • Dispose of spent solutions containing residues of the dyes responsibly. Dilute and pour onto waste land or into the sewage system. They have no known effect on the environment when used in the quantities recommended in the literature

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