During my recent woad-dyeing session, I happened to dye a skein that had been mordanted with alum. I was interested to observe that this alum-mordanted skein dyed a greener, more turquoise shade of blue than the unmordanted skeins. I wondered how I had failed to notice this shade difference before. I can only explain it as follows: Usually, I use unmordanted skeins for indigo & woad dyeing, unless I am using indigo to over-dye a skein already dyed in a dye that requires a mordant. As I always use indigo as the last dye in a 2 or 3-dye sequence, I suppose this was the first time I had used an alum-mordanted skein that had not already been dyed. As to why I always use indigo as the last dye in a sequence – I think this is because the depth of colour from indigo is easier to control than the depth of colour from other dyes. So by using indigo as the last dye, I can dip for a short time initially & then build up the colour gradually. I usually also reserve the other dyebath, in case I need to add some more of the first dye after the indigo (or woad) dyeing process.
Unfortunately my woad plants were ravaged by caterpillars this year, so I wasn’t able to harvest my usual heavy crop of woad leaves for the dyepot. The best time of year for harvesting & using the leaves is from late August/early September to the end of October. This gives the leaves time to develop their blue pigment. However, I have successfully used leaves for the dye vat at most times of the year, so it’s always worth using any leaves you can find, no matter the time of year. Also, although first-year leaves are generally recommended for the strongest blues, I have managed to obtain good blues from second-year leaves. Some of this year’s leaves were picked for a demonstration of woad dyeing in September at Denny Abbey in Cambridgeshire, where I regularly tutor natural dyeing courses. The last few remaining leaves were harvested this week in the pouring rain, ready for a woad-dyeing session with Chris Dobson, friend, fellow-dyer & plant expert. Fortunately, Chris brought with her some really large, “meaty” leaves to add to my rather pathetic specimens.
The blues Chris & I obtained from our dyeing session were as good as any from other sessions, so we were pleased with the results of our efforts. This is the method we used:
Collect about a bucketful of leaves, tear or cut them into small pieces, pour boiling water over them to cover them & leave them to soak for about an hour. Then strain off this liquid into another bucket & squeeze the leaves well to collect all the possible colour potential. Next, add enough washing soda crystals to turn the liquid from brown to green. To incorporate oxygen into the liquid in order to “activate” the blue, the liquid must then be poured from one bucket into another until the froth turns blue. Alternatively, the liquid can be whisked well. The process must be continued until the froth no longer turns blue & this can take quite some time. But persevere, no matter how much your arms ache, otherwise much dye potential may be wasted. After this pouring process, leave the liquid to stand for a while to allow the froth to subside. Then pour the liquid into a stainless steel dye pot & heat until the liquid is so hot that the heat is only just bearable to the hand. (Approximately 50C) Then add 2 to 3 teaspoons of sodium hydrosulphite to remove the oxygen & leave the vat to rest for about 20 minutes. By this time the liquid below the surface should be greeny-yellow & the vat is ready to use. Remember it is important not to introduce any oxygen into the vat, so add the materials to be dyed very gently so as not to cause bubbles. Leave the materials to soak for 5 to 20 minutes, depending on the depth of colour required, then hang them in the air to allow the blue to develop.
NOTE: More information on indigo & woad dyeing can be found in my latest book “Colours from Nature”. For further details about this book & how to order it, look under “My Publications” or email email@example.com
While visiting The Manor at Hemingford Grey (see entry on Bracket Fungus for more details) I saw a wonderful spreading yew tree (Taxus baccata) in the secret garden. This reminded me that yew wood shavings can give lovely orange & rust colours in the dyepot. So if you know a woodcarver, or have some other source of yew wood shavings, collect about the same weight of wood shavings to fibres you wish to dye & start off by pouring boiling water over the shavings & leave them to soak overnight.
Then simmer the shavings for about 1 hour & pour off the liquid to make the dyebath. Use wool mordanted in alum – I usually use 10% alum i.e. 10gms alum to 100gms wool – & simmer the wool in the dye solution for about 30 to 45 minutes. Leave to cool before rinsing. You can also experiment with colour modifiers for variations in shade. (See entry on Dahlias for further details).
As I rustle through the autumn leaves as I walk through my garden, I am reminded of one way of using these leaves for a dyebath. Don’t expect vivid reds, but fallen leaves will often give attractive, rich brown shades that are useful as a contrast to more brilliant colours. I usually pack a bucket full of fallen leaves, fill the bucket up with water (or wait & let the rain do the job), then leave the bucket in a corner of the garden until I’m ready to make the dyebath. (This soaking will extract some of the colour potential from the leaves.) Then I just transfer the contents of the bucket to a dyepot, simmer the leaves for about 45 minutes, then strain off the liquid to make the dyebath. Use an alum mordant for the strongest colours or, if you prefer not to use a pre-mordant, use an iron after-bath to intensify & fix the colour. (The entry for Dahlias gives more details of using an iron after-bath.)
At this time of the year many gardens are full of the glorious, vivid, glowing colours of dahlia flowers. To me they seem the floral echo of the wonderful autumnal shades of the leaves on the trees – the last flash of colour before the onset of winter.
As a dyer, these dahlia flowers are also a source of brilliant yellows, oranges & golds. With the exception of white flowers, which don’t yield much colour, all colours of flowers give similar shades & can be mixed together in the dyepot. The leaves give interesting green-brown shades, so to get the most out of the plants use the leaves for a separate dyebath, rather than adding them to the dyepot with the flowers. You don’t need to sacrifice the best flowers from the garden or flower vase – just wait until the flowers have faded & “gone over”, then remove them from the stalks. You need about the same weight of flowers (or leaves) to fibres for the most brilliant colours. You can use them fresh or dried, preferably with an alum mordant for full shades. After dyeing, the use of an alkaline modifier or after-bath will give vivid oranges. Just dissolve 2 or 3 teaspoons of washing soda crystals in boiling water, add this to cool water in a pot & soak the dyed fibres for half to 1 hour. DON’T heat, especially if dyeing animal fibres, as the alkaline solution may damage them. An iron after-bath will give mossy-green tones. Use half to 1 teaspoon of ferrous sulphate, dissolved in hot water then added to cool water, as described for washing soda. You can either soak the fibres in this for 10 to 30 minutes, or heat gently. You can also make your own iron water by soaking rusty nails or scrap iron in a solution of 1 part water to 1 to 2 parts clear vinegar. When the liquid looks rusty in colour, usually after 2 or 3 weeks, it’s ready to use. Just add a cupful of iron water to warm water & continue as above. Dispose of the used plant materials on the compost heap & remember that acid-loving plants or broad-leaved evergreens, such as camellias, will appreciate it if you pour iron residues around them. I usually pour the remains of iron modifier solutions around my blueberry bushes.
Copper sulphate can be used as a modifier in the same way as ferrous sulphate. You can also make your own copper water by soaking lengths of copper piping in a solution of 1 part water to 2 parts vinegar until the liquid looks blue/green in colour. Proceed as described above for iron water. Remember that copper is poisonous so handle with care.