Plant dyeing with Nature’s Rainbow, part 1

The advantage of the International Feltmakers Association’s regional groups is that they all organise their own workshops and activities to bring local felters together. But members of other groups are equally welcome if they are willing to travel.

So it was that I found myself heading for Ipswich a couple of weekends ago to attend a workshop on plant dyeing for felters, organised by Sally Sparrow of region 7. My god daughter lives in Manningtree, not far from Ipswich, and was willing to put me up for the weekend as well as drive me back and forth.

The workshop was run by Susan Dye (how’s that for nominative determinism?) of Nature’s Rainbow,  ably assisted by her partner Ashley Walker and weaver and knitter Brian Bond. As inspiration, they brought along samples of yarns, fabrics and fleece, plus knitted and woven pieces in a whole spectrum of strong, bright colours.

natures rainbow fleece and weaves natures rainbow dyed yarnnatures rainbow dyed fabric

Susan and Ashley grow their own dye plants on their allotment in Hitchin, specialising in grand teint – the medieval dyer’s guild term for the most light-fast and wash-fast colours. These include dyer’s weld (yellow), woad (blue) and madder (red).

As well as these, they also brought along other plants they had grown – dyer’s chamomile (yellow) and dyer’s coreopsis (yellowy orange) – for us to play with.

Although I have dabbled with natural dyes, it’s been mostly on silk, so I wanted to get some tips on the tricky problem of dyeing wool without felting. However, I learnt so much more that can be applied to all natural dyeing , whatever the fabric or fibre.

Mordants

Susan provided a very comprehensive handout on mordanting, including lots of safety information. There was lots of useful detail here – for example:

  • Dyer’s cream of tartar, often used with alum to help it dissolve, is different from baking cream of tartar, which has additives like anti-caking agents. If you can’t get dyer’s cream of tartar, it’s better not to use any at all.
  • Soak silk for at least 24 hours before mordanting – it is very resistant to wetting out.
  • After mordanting in alum, do not rinse the items immediately but store them damp for about a week. This is called ripening and really helps the mordanting. Then rinse thoroughly in cold water before use.

Hay boxes

A hay box is a non-electric version of a slow cooker, where you bring the food to the boil initially on a stove and then put it in a box insulated with hay, which preserves the heat and allows it to carry on cooking. It was a cooking method encouraged during the Second World War to save on rationed cooking fuel.

For dyeing, when you have to bring a pot of dye up to a certain temperature and then keep it there for an hour or so, a hay box can help save energy as well as on heating appliances.

 woad bath in hay box
Ashley’s woad bath in an improvised hay box

There are various sites that explain how to build one, but Susan and Ashley have improvised with cardboard boxes and old cool bags, lining them with old blankets, duvets, fleece jackets and the like. It’s particularly important to insulate the top of the dye pot, as this is where most of the heat escapes.

Yellows

We started with the yellows, setting up baths of dyer’s weld, dyer’s chamomile and dyer’s coreopsis. Chamomile and coreopsis give different shades of yellow, but they are less light fast than weld, so anything dyed with them should be kept out of the sun.

We poured boiling water onto the plants and then put the pots in hay boxes for an hour. Because only the chamomile and coreopsis flower heads are used for the clearest, brightest colours when dyeing, they also release their colour more quickly than weld, where the whole plant is chopped up. Then we strained out the plant material (using old tights!), and let the bath cool.

straining dyer's chamomile

The alum-mordanted wool (mostly organic merino from the Falklands) had already been separated into 50g hanks and wetted out well, so we put 50g in each dye pot and reheated to 70°C.

adding wool to weld

To get clearer, brighter colours from weld it needs to be kept below 70°C – at higher temperatures you get more of a straw colour. Then it was back in the hay box, gently flipping the wool once to minimise felting, until we were happy with the colour.

yellow dyebath

This was the basic method used throughout, with wool and silk repeatedly added to the dye baths until they were exhausted. Susan had brought along record cards to note the type of fibre, temperatures, times, and mordants, and was very insistent that the card stayed with each sample so that we knew exactly how each one had been treated.

coreopsis dyed wool

After cooling and rinsing, the wool was hung up to dry – we soon had a fine range of yellows!

Indigo and woad

In the afternoon the blues were introduced, with Ashley making up three baths: one from natural indigo stock solution, one from woad stock solution and one from woad powder. At home Ashley creates an indigo bath from leaves grown in his dye garden. The plants are harvested before they flower and the leaves are stripped off.

In the case of Japanese indigo, the leaves are put in cold water and slowly heated to 90C. Then they are left for an hour to cool to around 60C – the liquid is a greyish tan colour. After removing the leaves, alkali is added and the liquid is oxygenated by whisking or decanting it between containers. Once it has turned green it can be stored indefinitely in this form. (For woad, boiling water is poured onto the leaves instead of putting them in cold water and heating.)

To make the dye bath we added the reducing agent and checked the pH (for wool pH 8-9 is best).

The woad bath was rather weak – it turned out that the stock solution had been over reduced because the woad powder contained much less indigo than estimated.

woad dye bath woad dyed wool

However, overdyeing some of the yellow wool with the weak woad gave a fantastic lime green colour that was almost fluorescent!

Ashley explained that to get good greens the indigo or woad bath mustn’t be too strong, or the blue will overwhelm the yellow.

Coming soon in part 2 – We complete the rainbow with madder.

Advertisements

12 thoughts on “Plant dyeing with Nature’s Rainbow, part 1”

  1. Wow, what a great workshop. Such intense colors. It’s too bad the woad had weakened, but I’m sure it can be overdyed. Thanks for sharing.

  2. What an amazing workshop Kim to brighten up January. Thanks for taking the time to share your day and lots of useful information.

  3. What a wonderful array of colours, they look amazing 🙂 do you know how light / wash fast they are? I have always avoided these dyes, in part because of the mordants but mostly because so few of them are light fast but I see these are “grand teint”, will you be testing any samples to see if they really are light fast?

    1. Thanks Teri. I agree that light fastness is often a worry with natural dyes, though in fact synthetic dyes can have a similar problem (I’ve had faded curtains, and black T-shirts quickly become dark grey!). It’s tricky to carry out proper light fastness tests in the UK at this time of year owing to the, um, lack of light. 😉 But I will be putting some samples in a book with the ends hanging out and seeing what happens when left in a sunny spot.

      However, I’m more interested to see whether felting the wool (with alkaline soap) will affect the colour, as the colour of some dyes, like madder, is sensitive to pH. Susan suggested that this may happen but we didn’t have time to investigate during the workshop.

      1. I love experiments! Can’t wait to see the results of yours, I hadn’t considered the effect of PH, I had assumed the dye would be fixed but I guess possibly not if there is a risk of soap changing the colour?

      2. Dyers often use modifiers after dyeing to change the shade. This may be iron, to darken or sadden the colour, but could also be acid or alkali. I will be mentioning this in my next post on madder! 🙂

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s