Vegetable dye stuffs come in all kinds of shapes and forms;
Flowers such as St Johnswort and Goldenrod, roots like madder and Himalayan rhubarb. Our favourite leaves for example indigo and woad, nut hulls such as walnut. Berries from myrobalan, fruit seeds such as annatto. Fruit rinds like pomegranate. Heartwood comes in the shape of Fustic, logwood and many more.
And then there is bark.
For some reason my dye experience so far has been with everything BUT bark. I do like me a quick dye, so I think bark was just a bit too slow for my taste. It's best soaked for at least a night and as such does not lend itself for impromptu projects. But then there came corona, and "spontaneous" and "no time" were out of the window. Everything slowed down, including me and my work.
I like very much that it is organic, comes from a renewable source, and being that it is from Europe, I KNOW the people working in the industry are paid what they deserve and have their working rights respected. (This is honestly a thing I am very very keen on, and I double check all my suppliers regularly.)
Man plans and G'd laughs. Because of the pandemic, EVERYTHING slowed down including the postal services, so I needed to wait for a. very. long. time for my shipment to arrive, only to have it put in quarantine for another fortnight.
All samples were mordanted with 15% alum using 10% cream of tartar as an assist for protein fibres, and 15% aluminium acetate (powder, not homemade) for cellulose. I knew I would be doing so many samples soon, I mordanted around a kilo of pre-cut fabric which was a time saver overall. A Big BUT:
You do not have to mordant anything when dyeing with barks, they contain so much tannin that they self-mordant.
In fact, because of the high tannin rates, dyed fabrics may become darker when exposed to sunlight, this is something you see for example in Henna dyed textiles. I like this deepened saturation a lot! Some samples also got around 3% copper sulphate just to see what would happen, or a dip in light Ferrous Sulphate solution post-dyeing.
The good news; barks dye lovely on both protein and cellulose.
You should use at least 50% WOF for barks, and I do not shy away from 100% and just re-use the dye bath.
Soak your chips in tepid water for at least 12 hours. Seriously; do not skip this. Even better; soak them in tepid water and forget about them for three days. The cold process helps the tannins get out, which will improve your dye results. Start heating your dye bath with the chips in it, you can already add the fabrics at this stage but if you want to be a lot less messy than I have been; heat and decant the dye from the chips.
Protein; heat to 60ºC for an hour and a half and let the fabrics cool in the dye bath overnight.
Cellulose; bring to a low simmer for at least one hour, let cool down.
Always stir regularly so you do not create creases or patches in your dye works.
Chestnut is the strongest of them all; warm yellows with an orange tint, orange when used with copper.
Poplar gives sunny yellows, and dark ecru with ferrous sulphate.
Birch bark is the one to use for antique pinks.
Look at that difference between the two chestnut samples.
Re-use your dye bath by reheating and dyeing more fabrics, bark keeps on giving! You can keep the soaking and boiled bark bits for quite a long time to re-use. If it gets mouldy just skim off the mould and carry on. If you are a bit squirmish and you would like to keep your bath anyway; add three cloves at the beginning of your heating. The cloves have anti-bacterial properties and will prevent bacteria and mould from growing.
Use leftovers as an ink for water colour painting, best to boil it down a bit for more concentrated colours I suppose. I would not use these bark dyes for screen printing, I feel they lack the intensity needed.
Next project will be eco printing with these lovely barks, let me know what you plan on making!