Saturday, 21 July 2007

Traditional Natural Dyes

Attending a workshop on natural dyes gave me confidence to have a go at dyeing by myself. It turned out to be a simple process.

You start with undyed fibre or yarn, treat it by heating up with a mordant to improve dye take-up and lightfastness. Next, you heat up plant material to extract dye, and add the fibre or yarn. Different results with the same plant material are obtained by different using mordants, different fibre, different length of dyeing time and possible combining dyestuffs or dyeing the same fibre with two or more different dyes.

These are yarns I dyed last year, using traditional natural dyes purchased from a supplier of dyestuffs. I was impressed to discover what strong colours can be obtained from simmering plant material with wool. I hadn't been aware of natural dyes before I got Jenny Dean's book, and then had a go at dyeing for myself. I didn't expect these bright shades.

Left to right, the dyestuffs are: onion, weld, logwood, tumeric, madder and indigo.

Here's a group of shades from madder:

Blues from Logwood and indigo:

and a group of yellows, two skeins dyed with weld, and on the right, a skein dyed with buddleia flowers from the garden.

Encouraged by these results, I then decided to see what dye plants I could grow in the garden. Here are the results of using my own Dyer's Chamomile:

The wool (superwashed merino combed tops) was pre-mordanted by simmering for an hour with 10% alum (potassium aluminium sulphate) and 8% cream of tartar (potassium hydrogen tartrate). This percentage is calculated in relation to the weight of wool, e.g. with 100g wool, I use 10g alum and 8 of cream of tartar.

I picked a bowl full of flowers from the garden (do you remember the picture of my dye garden? there's no shortage of these flowers) and simmered them for one hour. Then I removed the flowers from the bowl and added the wool.

The sample to the left had a pinch of tin (stannous chloride) added at the end of the dyeing time, and was given another 10 minutes dyeing time. The green sample on the right was given a pinch of iron (ferrous sulphate) as after-mordant and also given just 10 minutes extra.

Now here's something I love about playing with the chemistry of natural dyes. One moment there is a pan containing pale yellow wool in a clear yellow water, add that pinch of tin and there is suddenly a swirling cloudy, orange developing and spreading in the pan. It happens fast! The wool is now orange.

Likewise, the pinch of iron. As it drops into the water and starts to dissolve, a deep green appears and spreads through the pan. Dramatic change! The wool takes the colour almost immediately, but a few extra minutes simmering gives stronger colouration.

1 comment:

Anonymous said...

Hello Dorothy,
I am very impressed with all the dying , all the experiments you have done. You have done a great job with the photos, documents and all the recepies! Your blog is very interesting, very precise about chemistry. Thank you!
I started beeing interested in natural dyes last spring and have been trying a few colors on wool, silk and cotton.
I came across your blog visiting the Online Guild of the Weavers, Spinners & Dyers, adress i was given by Stacey Harvey-Brown.
My blog and books are all in French, but if you care to visit: