Logwood on wool

Logwood (Haematoxylum campechianum, thank you Wikipedia) is a tree from Central America. Its name means 'blood wood' for reasons that will become obvious. It is a wonderful and powerful purple dye and can produce extremely beautiful lavender shades. Unless, like me, you mess it up completely.

Fabric: 200g wool
Dyestuff: 100g (50%) logwood chips
Mordant: 48g (24%) alum (aluminium potassium sulphate)
Colour modifier: small pinch, say 0.5g (0.5%) iron (ferrous sulphate) used on only one of the hanks

I started with some cream-coloured yarn from Rowan - Aran Pure Wool I believe. Lovely big squishy fat soft yarn. I'd generally go for white but cream's fine.



I bought my logwood chips from the fabulous fibrecrafts.com. It's a wonderful, wonderful website, stacked with dyestuffs, mordants and tools, and supplies lots and lots of other crafts apart from natural dyeing. I've recently placed an order on there for some paper marbling supplies - I may well share my marbling experiments on this blog.



As soon as the logwood chips touched water, the dye started seeping out from them - a bright, saturated magenta, much like Calpol. I wondered at this point what to do next. With onion skins you boil them up for 45 minutes to extract the dye, so is this necessary if the dye seeps out all by itself? I wasn't sure, so I did the extraction, which may or may not have been my mistake.







So far, so good. The dye seemed rather redder than I'd expected (I was aiming for more of a bluey lavender than a blood red), but you have to embrace happy accidents with natural dyeing - plus the blood red is a beautiful colour, so I wasn't complaining.

The trouble started when I dropped my mordanted yarn in there.



That's not blood red. That's not even purple. That's black. Black black black. As Spinal Tap would say, "The question is, how much more black could it be? And the answer is none. None more black."

I'd done a lot of reading on logwood before I started this experiment, and everything I'd read had said that logwood produces a light or bright lavender/purple, but plunges very suddenly down to black as soon as you add iron or copper as a colour modifier. Fine, but I hadn't added either at this stage. So what's going on?

After a while, the pot had started to bubble a bit, and the bubbles were almost exactly the colour I'd expected the yarn to be: a bluey lavender.



I did end up adding a tiny sprinkle of iron to one of the hanks. My reasoning at this point was that the yarn was essentially black, so it didn't really matter any more whether I added a darkener or not - but I might as well, in the name of experimentation.

The resulting balls of yarn are very very very dark purple. Black in most light, slightly violet when the sunlight catches them. Black in artificial light.



So what went wrong? I'm honestly not sure. One theory is that, somehow, I managed to contaminate the dyebath with copper or iron. I don't know how this could have happened, but I guess it's a possibility. Another is that my recipe is wrong and a 50% dyebath is just way, way too strong - I've found a website (the lovely True Fibers) which says to use "12-50%", although I'm wondering if 5% is more like it. A third theory is that there's something about my logwood, like it's ground much finer than usual or something, which I guess would greatly increase the surface area and therefore cause a much stronger bath than I'd intended.

Not that my resulting yarn isn't lovely - it is - but it's just far, far darker than any examples I've seen in books or online. I have a second bag of logwood chips so at some point I'll have another go with something like a 10 or 12% bath - I'm now even more determined to get a good lavender.

Oh, incidentally - my pan was heavily stained purple after all of this. I tried bicarb to get it off, but it had no effect at all. Then I tried my new friend, washing soda, which zapped it straight off. Yay! It really does do everything.

Books on dyes

Incidentally, I have a few books on natural dyes. My favourite one is 'The Craft of Natural Dyeing' by Jenny Dean.

Amazon link

Onion skins on cotton

Another go with onion skins before I move on to the fancier ingredients (which I'll have to do since I've now completely emptied my shoebox full of onion skins). My main aims for this dye job were threefold: to figure out dyeing plant fibres (quite different from animal ones), to work out whether my last one went patchy because I soaked two different hanks together, and to use iron without turning everything completely black.

Fabric: 100g cotton
Dyestuff: 45g (45%) onion skins, mixed yellow and red
Mordant: 25g (25%) alum (aluminium potassium sulphate) with 6g (6%) washing soda (sodium carbonate)
Colour modifier: small pinch, say 0.5g (1.0%) iron (ferrous sulphate) used on only one of the hanks

The way that plant fibres, such as cotton and linen, behave during the dyeing process can be quite different to the way that animal fibres (wool, silk, cashmere) behave. In some ways the process is easier - because you don't have to be anything like so careful with the fabric - but it can be harder to get the dye to take.

First challenge was tracking down some sodium carbonate, also known as washing soda. Washing soda is one of those old-fashioned products like Vaseline, bicarb or vinegar which doesn't seem to have been intended for any one purpose, but over time has been found to have dozens of uses. The back of the bottle says To shift heavy stains from clothing; to unblock sinks and drains; to degrease cookers, pans and barbecues; to soften water for laundry; to remove moss from paths. Crikey! Is there anything it doesn't do? I'm reminded of a Mad magazine feature from years ago about finding other uses for baking soda (to dust for fingerprints; to lubricate noisy corduroy trousers...). Eventually I found my bottle of washing soda crystals at the endlessly useful Robert Dyas and it was only 99p. Hooray!

The best thing about dyeing cotton, as opposed to wool, is that it won't felt. This means you don't have to bother with all that 'put the yarn in cool water and gradually bring it up to temperature' stuff. You can just drop it into boiling water, and when you want it cool you can just throw it under the tap. This does make it all a bit faster.

To scour cotton, you can just boil it, so you don't have to soak it overnight. Unfortunately, though, this doesn't mean that dyeing cotton is vastly quicker than wool because the best way to mordant cotton is to boil it up with the alum and washing soda and - yep - leave it soaking overnight. I was a bit worried here as the alum seemed to react with the washing soda - something white precipitated out of the water and formed a sediment on the bottom. Somehow this felt strange (why are my chemicals not sticking to the yarn?) but I don't think it mattered.

From this part onwards it's all the same as wool. I did notice a significant difference, though - the dyebath didn't begin to clear while the yarn was in there. Furthermore, when I came to rinse the dye out of the yarn, masses and masses of colour came out and I had to rinse the yarn a lot before it ran (nearly) clear. This wasn't the case with the wool, to which the dye seemed to stick like superglue. I suspect this means that natural dyes are more fugitive on plant fibres - I wonder if it will fade faster?

This time I used much less iron than last time. Deciding that my kitchen scales are nowhere near sensitive enough to measure out a gramme or two, I sprinkled a little bit in instead - I'd say about quarter or half a teaspoon, maybe 1g, maybe less. I also made sure to soak and rinse my two hanks separately to prevent iron contamination crossing from the darker to the lighter hank.





Success! No dark iron-contamination patches on the lighter ball this time, and the darker one is nowhere near as dark as with the wool. I'm pleased with these results and now feel prepared to move on to some of the more unusual dyestuffs.

Onion skins on wool

For my first trick, I will be dyeing two hanks of wool with onion skins on alum.

Fabric: 100g wool
Dyestuff: 50g (50%) onion skins, mixed yellow and red
Mordant: 8g (8%) alum (aluminium potassium sulphate) with 7g (7%) cream of tartar
Colour modifier: 1.5g (3%) iron (ferrous sulphate) used on only one of the hanks

Since this is my first dye job, I'll describe it in detail. Future posts will be less verbose.

To start with, I took my two 50g balls of wool and tied them into hanks. The first step is 'scouring' which means getting all of the oils and grease off the yarn. To do this, I put a little splash of washing liquid (non-bio) into a big pot of cold water and soaked the yarn overnight.



After draining and rinsing the yarn, I measured out 50g of onion skins, which is a lot! It nearly filled my stockpot.



I then poured boiling water over the skins (enough to cover, plus a pint or so more), brought it to boiling point and simmered for 45 minutes.





After it had cooled, I strained off the onion skins and threw them away. Note to self: don't squeeze out the water with your bare hands unless you want yellow-brown fingernails for several days afterwards. Marigolds are your friends.

After this I ended up with something that looked rather like a prop from Carrie.



Now to mordant the yarn. This bit is boring, and next time I will do it at the same time as the dyebath preparation. I simmered the yarn in alum and cream of tartar for 45 minutes at 82 degrees. You have to be very careful not to 'shock' the wool by subjecting it to sudden changes of temperature - so bring the temperature up from cold at the beginning, and let it cool slowly again at the end before draining and rinsing.



Next I plonked the mordanted yarn into the dyebath and brought it back to 82 degrees for 45 minutes. This bit's actually quite interesting because you can see the colour come out of the dyebath and go into the yarn, so the water begins to clear.





Next I fished out both hanks of yarn. Note to self: buy some tongs unless you want to burn your fingers doing this. I wanted to try using iron as a colour modifier, but only on one of the two hanks so that I could compare the results. I tried to measure out 1.5g of iron but my scales aren't really sensitive enough, so it might have been a bit more than that. It certainly looked like I'd gone a bit overboard when I sprinkled the iron into the dyebath - below you can see the colour of the bath before and after stirring.





That second photo isn't clear, it's black, but hard to see.

I then returned one of the two hanks to the dyebath and simmered for five minutes longer before fishing it out and leaving it to cool.



Once cool, I soaked both hanks together in new fresh water to help get the last bits of dye out. I suspect this might have been a mistake but am not sure yet - see for yourself:





Now, part of that rather startling colour change is likely to be because I took the first photo under the crazy halogen lights in my kitchen, and the second in natural light. But there was definitely a significant transformation from saturated orange to a kind of tobacco/ochre during the soaking process. There are two possibilities here: either it just always happens - the colour matures for a few hours after it's left the dyebath - or it's because I sat it in water with the iron-modified hank. After all, there was bound to be some ferrous sulphate left on the darker hank, which could well have made its way over to the lighter hank while they soaked. The patchiness of the lighter ball would support this theory since maybe bits of it that were closer to the darker hank picked up more iron... maybe? Not that I mind since I like variegated yarn, but I wasn't expecting it since I did lots and lots of stirring throughout the whole process.

My other main observation is that the yarn did shrink an awful lot, both in length and width. It started out as... erm... DK I think, possibly aran weight, but now it looks like 4-ply. I think I might try to get superwash chunky wool for future experiments. Maybe cotton wouldn't shrink as much?

Next time I will soak and dry the hanks separately. I will also bother to put on my rubber gloves more often - to avoid the stained fingernails - and I will buy a pair of tongs. But I am pleased with my first experiment. I think I will twist the two yarns together and knit a hat, when I next have a free couple of evenings.

Quick blog explanation

This blog concerns natural fabric dyeing, which is all about colouring yarns and fabrics using onion skins, madder, weld, indigo, logwood, woad and many other plants (and insects). I've been getting interested in this lately, and have decided to record the results of my experimentation here. This may end up being one further post, after which I'll lose interest; or it may end up being a lifetime's obsession. Don't know yet.

The main purpose of the blog is to serve as notes for my personal reference, but if you've found your way here, you're very welcome to have a read. Maybe you'll find something useful.

I don't expect posting to be frequent as natural fabric dyeing takes ages and it's rare that I find enough free time to do it. I hope to be able to make time, though, because dyeing is super-duper awesome fun.

Beverly xx

P.S. I'm not actually a doctor, nor do I have a laboratory. I did chemistry A-level, though... does that count?