Wednesday, March 23, 2011

Natural Dyeing: step by step dyeing with onion skins

Thanks to the miracle of modern medicine (reconstructive back surgery) I was able to ride the wave of my first shibori dyeing post and run the dye pot I've been wanting to do for over a year! When I looked in my notebook, my last recorded dye session was March 2009, so it was high time to get to it again. On the other hand, having to wait until my back was reconstructed (because I couldn't even imagine lifting heavy dye pots the way it was before surgery) allowed me to save a load of onion skins Unlike some folks I know, I tend to save them over time rather than go to the grocery store & ask for what's in the bottom of the crates. So it takes a while to save them up (although I'm pretty meticulous about saving them- there's a ziplok bag in the kitchen where I put them as I make meals, which gets emptied into a bigger bag in the basement).  I decided on Monday to start the process & fit the rest of it in & around my activities on Monday & Tuesday.  Today, as you can see above, I have 8 beautiful skeins of onion skin-dyed wool. I thought I'd document things as I went along, so I could blog the step-by-step process that I use to turn onion skins & wool into beautifully coloured wool :)

I learned what I know about natural dyeing from books mostly, & from some communal dyeing with friends from my local spinning guild. The main book that I use is Jenny Dean's Wild Color, with an understanding that natural dyeing is the least reproducible of the arts, & what may seem like unexpected or disappointing results from one perspective can be beautiful colours from another. In other words, I haven't always gotten the results Dean publishes in the book, but it's a very good place to begin, technique-wise. I have been natural dyeing for more than 10 years, and documenting everything in a notebook has resulted in the best resource possible for natural dyeing :) I try to record results as well as process, so that I won't forget, for example, that silk needs to be removed from a brazilwood dyebath before it boils or the colour will leech right back out.

Before I begin the step-by-step, I want to mention some terms & procedures. The first is "weight of goods" (sometimes abbreviated as "WoG"). Weight of goods refers to the weight of what you're going to be dyeing, & it must be weighed dry. WoG is used to determine the amount of mordant used to fix the dyes in that material, & sometimes used to determine how much dyestuff to use as well. Another very important thing to remember is when handling wool & boiling water, always go from cooler temperature to hotter temperature. If you plunge wool from a boiling vat into cooler temperature water, it will felt. But if you always go hotter, you minimise felting. And although you do stir the yarn in the dye bath, doing it slowly not only minimises felting but prevents scalds from splashing boiling dyebath. When weighing things, I use the metric system- partly because it's easier to calculate percentages in a base-10 system, & partly because all of my scales are metric. Mordanting requires precise measurement, but if you have to estimate a bit, estimate higher so you don't under-mordant your materials.

And, of course, what is mordanting? Well, you can boil wool with pretty much anything & get colour to stick, but unless it's a particular dyestuff (like rhubarb leaves, black tea, or black walnut, which all contain tannins) the colour will be fugitive, or non-lightfast. Protein fibres, like wool & silk, will take dye the best- bast fibres, like cotton & linen, are harder to prepare in a way that natural dyes will stick to them, hence the need for (& popularity of) aniline dyes. The best way to make protein fibres lightfast is to mordant them with chemicals that create a chemical bond between the dye & the thing being dyed. Many mordants use heavy metals & are extremely toxic, but a few- like the above-mentioned tannin-containing materials- as well as alum, are much safer.  Rhubarb leaves are toxic when ingested, so keep it away from the kids. Of alum, black walnut, & black tea, alum is the only one that doesn't act as a dye on it's own. so it's the best choice for mordanting anything you don't want to turn brown... :) Alum is used in conjunction with cream of tartar- I didn't really understand why until recently, reading an article at Geek Mom that explained that cream of tartar is a mild acid. I think that the cream of tartar (or "CoT" in my shorthand) balances the pH in the face of the alum, which is a mild base. Protein fibres take up dye better in an acidic environment, so this is my theory as to the use of CoT with alum.
alum & cream of tartar for mordanting

The first step in dyeing is to prepare what you're going to dye.  I decided to dye some Lion Brand Fisherman worsted wool. This is one of the yarns I usually choose because it comes in big, 8 oz (227g) quantities, is affordable, & I can buy it at my local JoAnn Fabric store. I decided to dye both white & natural grey Fisheman wool this time, just to see what I'd get. My other favourite yarns to dye are from KnitPick's Bare line of yarns. These are also affordable, in large-sized skeins, and in a bunch of different weights & fibre contents. This time I went for 2 fingering-weight yarns, the Gloss 70% merino/30% silk & Peruvian wool. These are in 100g put-ups, already skeined, but I add 2 more ties to prevent tangling. The Fisherman needs to be put into skeins before dyeing:

And then the skeins tied loosely (I alternate between the ends of the skeins of wool as ties & crochet cotton) in a figure-8 tie:

I use my niddy-noddy to put them into ~230 yard skeins, dividing each 8 oz ball in half. I also add tags made from washable interfacing, labeling the name of the yarn & the yardage or fibre content:

Because the Fisherman yarn still has some lanolin in it, & lanolin inhibits uptake of dye, I scour the Fisherman skeins before mordanting:
To scour wool, I run the hottest water from my taps into a basin or kitchen sink. Once the water's in, I add a few squirts of grease-cutting dish soap & gently swirl it around (trying to minimise bubbles here, folks). Then I gently sink the skeins into the soapy water. Then I wait at least an hour for the water to cool down. It's a bit smelly at this point, but it's a nice smell :) When I can safely put my hands into the water, I lift out the skeins, gently squeeze, set them aside, empty the sink, & fill it again with hot, hot water. No soap this time, just sink the skeins back into the sink & push them under. Wait, again, & then when you can put your hand in, they're ready for mordanting. If you don't scour (& I don't scour the KnitPicks yarns because they don't have detectable grease in them) you still have to wet them thoroughly before mordanting, so I tossed the KnitPicks skeins into the rinse water with the Fisherman skeins to really wet them.

Then, knowing the weights of the combined skeins of yarns from the label (3x 227g balls of Fisherman + 2x 100g skeins of KnitPicks wool= 881g WoG) I measured my mordants. The ratios I use are 10% WoG for alum & 5% WoG for cream of tartar, so I measured ~90g of alum & ~45g of CoT (using an old yoghurt cup). I half-filled my big mordanting pot with hot water & added the mordants, stirring well. Then I added more hot water to ~3/4 full. I added the wetted skeins to the pot, stirring them gently but completely into the water. It's important to keep the skeins moving as you go, so they don't take the mordant (of the dye, for that matter) unevenly. I use an old metal spoon for this, but an old wooden spoon, dowel, or anything heat-resistant will work. Then I put the pot on the stove & put the heat to high. I use an old rag or cottage cheese lid as a spoon rest while dyeing.

A brief word about tools- never use food cooking pots for dyeing, not matter if you're using food-safe dyes (or dyes that are food...). Although I can get a bit lassaize-faire with my measuring equipment when using alum, etc, I routinely use dye pots (& spoons, bowls, colanders, etc) for dyeing & keep them in the basement when I'm not dyeing. Dye pots get stained over time, too, & not all dyes are safe around food, kids, & pets, so it's just sensible to be careful.

Back to the mordanting:
The wool tends to float to the top when it gets hot, so that's another reason to stir gently every 5-10 minutes. Also, the skeins need room to move so try not to over-fill the pot. Nearly 900g of wool was pushing it a bit even for my big pot, so stirring regularly became even more important. It can take up to half an hour to reach boiling, so I put the lid on to speed things up. Don't leave a pot near to boiling or you'll have a mess & maybe more. I once left a simmering pot (distracted by my then-small child) & smelled gas about 15 minutes later. The pot had boiled over, put out the flame, & my kitchen was filling up with natural gas (!). I was able to ventilate things & disaster was averted, but I learned an important lesson! Bring a book or something while you wait. Once it reached a boil, I set a timer to 1 hour, turned the heat down low, put the lid back on, & let nature take it's course :)

If you are inclined, you can make the dye bath while you're waiting. I didn't have time on Monday, so I turned the heat off after an hour & just let the pot sit for the rest of the day (safest way to handle hot skeins is to let them cool first :). My understanding is that the mordant is completely taken up during this process, so you could reuse the leftover water for another mordanting session, (add more mordant) or even for making dyebath, if you want.

On Tuesday morning I excavated the onion skins from the basement where they'd been waiting for so long. I actually had 2 shopping bags full of them, but was reminded that onion skins have a mind of their own, being so crackly, light, & fluffy. So I was only able to jam one bag full into my big dye pot.
I added water until I could see it (the skins floated up some), but made sure it was a good distance from the brim, because I didn't want any boil-overs. Then I put it on high heat:
Here's the pot with the steam just coming off. When not taking pictures I put the lid on (to speed things up & save energy):
When they reached the boil, I did the same as with mordanting- gave them a stir, turned down the heat, put the lid on, set the timer for an hour, & let nature take it's course. Here they are at the end of an hour:
Then I prepared the strainer while the skins cooled a bit. I took the cooled skeins out of the mordant & set them in a bowl so I could use the mordant pot to receive the strained dye. I used cheesecloth because I had some hanging around, but muslin works well, as do old curtains :)
Do let the skins cool for at least half an hour before straining them, because they really splash when they're hot & you could be burned.
I let the whole thing sit in the strainer for a few hours (I had some errands to run) before gathering up the cheesecloth & squeezing it out by hand (thus staining my hands orange for the rest of the day...).

I added water to bring the pot to 3/4 full, stirred it, then added the still-wet, mordanted skeins. I only added 5 of them- 2 white fisherman wool, 1 grey fisherman, & both KnitPicks skeins. I saved the other 3 skeins for the exhaust bath, for lighter shades.  I added the skeins as quickly as possible, because I've had mordanted skeins pick up the dye so quickly that easing them in slowly caused uneven shading.
The dye bath looks a bit murky, doesn't it? Onions skins are one of the few dyes I use that doesn't completely exhaust (ie: the colour gets all used-up) & it always has this murky look- who knows why. Anyway, I put the heat on high, put the lid on, & stirred every 5-10 minutes until it reached a boil.
You can see (through the steam) that the murkiness clears up as the dye is absorbed into the wool. It's amazing to watch- the skeins get oranger & oranger & the dyebath gets more translucent as the heat gets higher. I simmered the skeins for an hour, then turned off the heat & carefully lifted the skeins out with a spoon.
Before the dyebath had a chance to cool too much, I added the remaining 3 skeins for the exhaust bath.
And then I repeated the same process for them. Meanwhile, I ran hot water into a bucket in the basement & put the first dyebath skeins in to rinse:
After half an hour, I repeated the rinse (lifting the skeins out before emptying & refilling the bucket). By the time the exhaust skeins were done, I could take the first bath skeins out & rinse the exhaust ones. Then, once rinsed, I spun them all on the "spin-only" cycle of my washer & hung them to dry overnight.
From left to right: top row is first bath- KnitPick's Peruvian wool fingering, KnitPicks Gloss fingering, 2 skeins Lion Brand Fisherman white, 1 skein Fisherman in grey. Bottom row is  the exhaust bath skeins- 2 skeins of LB Fisherman in white, 1 in grey.

I find it really interesting how different wools will take the dye differently.
The LB Fisherman white skein on the left is a slightly different tone from the KP Peruvian in the middle, & the Gloss fingering (with silk in the blend) is a golder shade.

And here are the LG Fisherman skeins, L-R: exhaust bath white, first bath white, first bath grey, exhaust bath grey. All these different colours from the same dye bath! This is why I just love natural dyeing! It takes some work, but it's like watching a miracle as it's happening.

If you happen to try this, please share your results & observations in my comments section. Thanks!


  1. Lisa!
    What a fantastic blog entry!! I just love it! Thanks again!

  2. Thanks so much for your comment! I hope you'll find this info useful.