There are many factors to consider when dyeing fibres with naturally occuring dyes from plants and other materials.
- Most dyes require the fibre to be first treated with a mordant solution. A mordant is a substance which binds the dye to the fibre. The most valuable and commonly used mordant is Alum. Other mordants, such as tin, iron, chrome and copper will alter colour results. These are the names used by dyers for the mordant, a more detailed description of the chemistry involved can be widely found on the internet.
- Different types of fibre will accept the dye in different ways. Wool, silk and mohair are animal (protein) fibres, while cotton and linen are plant (cellulose) fibres. Fibres from the same group will often take up dye colours differently.
- The pH level (acidity or alkalinity) of the water used in the mordant solution and in the dye bath will also affect the colour results.
- The method of extracting the dye colour. Is the dye stuff soaked over night? How long is it 'cooked' for? etc
- Quality of the dye stuff. How was it dried out? How has it been stored?
The great skills of the Professional Dye Houses in Medieval times very quickly becomes apparent. The craft of producing consistent and subtle colours from nature will therefore appeal to those with an experimental and organised approach. Many books have been published by experts on the subject and a selection is available from our Book Shop.
Here we share Allison Holland's Natural Dyeing experiment with Alum, Logwood Chips and Fustic Chips on a selection of fibres:
I've never dyed anything with natural dyes before and did a quick review of the process before collecting together my dye stuff (I chose Fustic Chips and Logwood Chips, photographed top right, and Alum) and swatches of fabric and yarns (top left to bottom right in the image below: Merino wool prefelt fabric, cotton fabric, silk fabric, Mohair yarn, 80% wool / 20% nylon yarn, and paper yarn). The great advantage of using these specific dyes is that they will dye both protein and cellulose, while many of the other naturally occurring dyes will only dye protein fibre such as wool and silk and will require a mordant.
Remember any tools used for dyeing (including saucepans and measuring jugs) should not then again be used for cooking food.
I first weighed my swatches which were just under 100g and then made a 20% solution of Alum in boiled water. 10% = 20g in 200ml water. After wetting my swatches in water, I squeezed out the excess and then covered in the mordant (Alum) solution. While the items were soaking in the solution, I put the 100g of Logwood Chips and Fustic Chips each in a mesh bag and covered the bags with boiling water in their own saucepan (much like making a cuppa!). I allowed the dye stuff to simmer on the stove top for about 45 minutes and then squeezed out the mordanted fibre before putting equal quantities in each of the saucepans. These were left these to simmer for a further 45 minutes.
I drained off the dye stuff and rinsed the items until the water ran clear. Here is an opportunity to learn from my mistakes!
The image above shows the results from dyeing with Fustic chips, most of the items are a mustard yellow colour (which looks great on the silk fabric) and the cotton and paper yarn are a creamy colour.
The first thing I realised (after checking the reference book once I'd finished!) was that I had not mordanted the materials properly as they were not allowed to soak for long enough and the mordant solution should have been heated. Different books and different web pages offer conflicting instructions and the colours may have been brighter if I had followed the instructions in at least one of them. I did rinse the fibres out quite thoroughly and the dye does appear to be wash fast.
Another mistake I made was to assume that all the dye stuff was contained within my mesh bag and it wasn't until I drained out the dye solution that I realised there was quite a lot of dust stuck to the material making some of the colouring quite blotchy. I should have removed the dye stuff and strained the solution first before adding my materials.
Below is a photograph of the items dyed using Logwood Chips. I love this colour! All the items came out quite blotchy, except for the Mohair yarn and the Wool yarn and I'm sure this is because, firstly I didn't mordant the swatches properly and secondly because I didn't strain the dye solution. Another factor is because the dye vat (or my saucepan in this case) was not big enough to allow the dye to cover the material evenly.
If you would like to try this for youself at home, please browse our selection of natural dyes and mordants.