Dyeing vegetable fibres

The Process to Dye Vegetable Fibres

Diane Culpin

Anyone can dunk a skein of linen or bolt of cloth into a fermentation vat and hope to stain that item to a pleasing colour that lasts today and for years to come. Unfortunately that’s easier said than done. Dyeing requires a solid knowledge of the fibres to be dyed and how to apply and make dyes that are reasonably ‘fast’. So, in an effort to keep this article manageable, I will now focus only on the techniques used to dye the linen mentioned above.

Linen is a vegetable fibre. That in itself means it is more difficult to get a natural dye to ‘fix’ to the threads. The linen fibre is highly resistant to dye chemicals ‘permanently’ bonding (attaching) to the outer surface or penetrating into the thread itself. Therefore you must treat the fibre with two different chemicals to facilitate (or assist) the absorption of colour. The dye will then attach to the chemical which has bonded to the threads. The steps for vegetable fibre dyeing are as follows:

1. Wash or scour the yarn or cloth to remove dirt or sizing that was applied.
2. Any vegetable thread must first be treated with tannin, which will bind to the surface.
3. A mordant can be applied which will then assist better colour take-up. Note that some dyes do not require a mordant.
4. Dyeing. Obtain a dye solution from natural materials. An alkaline dye solution will improve colour take-up.
5. A modifier or additional mordant can be used to change the tone of the colour – brighten, sadden, etc.
6. Return the fibre back to its natural pH by rinsing in a slightly acid solution.
7. Rinse in water and then wash with a mild soap.

Please realise that this process is generally not something that can be done in a few hours, but more likely several days to a week or even longer. Much depends on the intensity of the colour you wish to achieve.

Tannin

Appropriate period tannin can be obtained by using the following: oak galls, elm bark or staghorn sumac leaves are high in tannin. The ratio is 60g oak galls, elm bark or 50g sumac leaves to 100g of fibre. Pour boiling water over the plant material then simmer for an hour, follow this up with allowing the concoction to soak overnight at the very minimum. A day or two is fine as well. Strain the liquid.

Heat the tannin solution to almost boiling. Immerse the material into the solution ensuring there is enough liquid to allow the material to move freely. As I was using 5 metres of cloth, I mordanted in my bath (yes, my husband was less than amused! and note that you will need to bleach your bath (if it is a white one like mine) afterwards because the solution will stain. Again, leave this to soak for several hours or overnight, swirling the cloth occasionally and keeping it immersed. When finished, rinse fibre in clean water. When dyeing smaller amounts you would immerse first and then heat the solution.

Alum

Alum was used as a mordant during the Dark Ages. Period alum can be acquired by using a solution made with oak galls, clubmoss, evaporates from sea water, stale urine, or seaweed. So yes, if you use oak galls you can take one step out of the picture. A ratio of 50g of ‘alum’ material to 100g of fibre should be sufficient. Cream of tartar is also used in an alum solution to improve the take up of colour. Period cream of tartar can be obtained by the white crystals that form in a wine barrel. 1 ½ teaspoons per 100g fibre is appropriate for the cream of tartar.

Again the process of:

1. Immerse the fibre
2. Heating the solution (after extracting the alum) and simmering for 1 hour
3. Soak for several hours or overnight agitating occasionally
4. Rinse in clean water.

Now your linen is ready to dye!

Credits: with thanks to an article by Diane Culpin.