But how much mordant do you really need?

 Blog

This is THE question, isn’t it? I think a lot of people, myself included, just start with a formula they find somewhere but don’t take the time to test it against other options. The good news is, I’ve done a test for you. I’ve done a mordant strength test with aluminum acetate previously; this is a mordant strength test with potassium aluminum sulfate, aka, alum mordant for protein fibers.

My underlying question in doing this experiment is how best to handle wool, alpaca and silk blend roving— how much heat, agitation, time and mordant gives the best result? And do I need to use cream of tartar (potassium bitartrate)? My preferred outcome will be good color uptake while still having a nice hand and easy spinability.

The first recipe I came across was from John and Margaret Cannon in Dye Plants and dyeing, which uses 18% WOF alum and 6% WOF cream of tartar. I started using it and had good results, but in my natural dye class we use 10-15% alum with no cream of tartar. I usually bring my mordant bath up to temperature (about 160-170F), turn off the heat, and let my fiber sit overnight. In class (where we generally use fabric samples, not yarn or roving) the fiber is at constant temperature for an hour (170F or so— not boiling, but steam coming off the water) and then removed and rinsed. The least amount of alum mordant I’ve seen used is from Jenny Dean, just 8%, but with 6% cream of tartar.

This experiment is my fairly best comparison of apples to apples to apples, starting at the low end of 8% alum, ending at the high end of 18%, and splitting the difference at 13%. All mordant strengths are tested with and without cream of tartar, and processed at heat (170F) for one hour, or brought up to heat and then turned off and let sit overnight, for a total of 12 different samples. Both wool, silk, wool/silk blends and a silk/plant fiber blend were sampled, in the form of fabric and also commercially prepared organic undyed yarn. All samples of the same mordant bath were processed together, and all samples were wetted out for at least an hour. In the end, ALL of the samples went into the SAME dyepot of 20% WOF cochineal, a good strong dyepot, with the hopes of disambiguation.

There were some interesting results!

Even before I mordanted anything, the visual difference between the alum with/alum without cream of tartar bath was obvious. With cream of tarar, the bath was clear. Without, it had a cloudy, milky look. This persisted after the fiber was removed from the mordant bath. The ph of each bath remained the same, about 3-4.

After I’d mordanted my samples, but before I’d dyed anything, I tested the hand, or feel, of all my samples— the common complaint about increased alum strength is that is can make the fibers feel “sticky”. With all of my wool samples, regardless of alum%, those without the cream of tartar felt coarser. The yarn especially felt sticky without cream of tartar. On the silk noil samples, the samples WITH cream of tartar at 8% mordant strength had a more noticeable yellow cast . The hand of the silk noil and habotai were not discernibly different, but the silk-faced plant blend and the wool/silk were definitely smoother/nicer with the 6% cream of tartar.

So what about the color? Take a look! These samples are all laid out in a 4×3 grid as follows:

8% 1hr, 8%/6% cream of tartar 1hr, 8% overnight, 8%/6% overnight

13% 1hr, 13%/6% 1hr, 13% overnight, 13%/6% overnight

18% 1hr, 18%/6% 1hr, 18% overnight, 18%/6% overnight

Silk/hemp blend— my “control”. In real life I’d use aluminum acetate to mordant this.

Silk habotai. The cream of tartar definitely helps the dye uptake, especially noticeable at the lowest strength mordant.

Silk noil. The unevenness of color I attribute to not enough wetting out time. In the future anything with silk will soak overnight.

This is a thin 60%silk/40% wool twill. I was surprised that I liked the 18%/6% 1hr mordant the best.

Medium weight wool challis. Not as great a difference between the 13% and 18% mordant strengths as on the silks.

Commercially prepared undyed organic merino yarn. I didn’t scour it, and I should have! I think the color uptake at all mordant strengths would have been much better. The 18% overnight skein is missing— I ran out of yarn.

Takeaways:

Its pretty clear that more mordant equals more dye uptake. This was a strong dyebath, with plenty of color left over (I dyed several more yards of fabric afterwards with the leftover bath). Between 13% and 18% the difference isn’t as stark as at 8%, so I might do an additional test at 15%WOF and see if I can see a big enough difference to merit the additional mordant.

It’s not so clear in the photos, but the samples mordanted on heat for one hour had a nicer, more even color than the ones brought up to temperature and then left to cool overnight. This surprised me. In the future I will probably keep on heat for one hour, then let cool naturally before removing the fiber. This has also dissuaded me from trying a recipe I found on the internet for mordanting in cold water!

I will definitely be wettting out silks overnight, and scour any fiber I haven’t already prepped myself. I will use cream of tartar, for both mordant uptake and nicer hand. The final test, of course, is a light-fast test. My hypothesis is that the higher mordant strength will be more fast.

Light-fast test in progress.

At this point I’m of the opinion that the prep work, from scouring through mordanting, is the key to nicely dyed fiber. The dye bath is basically proving how good a job I’ve done. A stronger dye bath won’t produce any more color than the amount of mordant bonded to the fiber. This test was done with cochineal, which won’t dye without some sort of mordant; if I was dyeing with something substantive like onion skin, the extra mordant strength may be unnecessary.

I hope this helps answer the question of how much mordant *you* really need: by all means, do your own experiments!

Surface Design with Natural Dyes

 Sally Williams

 Blog

Rachel: “I found these cute block-printed throw pillows I want to make. How can I do that with natural dyes?”

I’m mostly a spinner and knitter, but in the natural dye classes that I attend at OCAC, there are a lot of people who focus on textiles. We’ve used a simple technique to get a lot of different results, and it’s really a lot of fun.

You will need the items you wish to print with: print blocks, stencils, potato stamps, paintbrushes, silkscreens, or anything else, and a few pieces of equipment: a blender, a steamer, an old bedsheet, and gum tragacanth. Gum tragacanth is a natural product that is most often used making fondant for cakes. Here it’s used as a “sticking” medium. What’s good about gum trag vs. other similar products is that it doesn’t interfere with or change the color of your dyestuff.

The technique: mix up some gum trag and water in a blender. Say, 1/4 C gum trag and twice a much water. You will hear and feel the mixture get thicker after about thirty seconds. If it’s too thick, add more water. If it still seems a little runny, let it sit for a bit, it thickens over time. Don’t mix more than you’ll need for your project at hand, because it only lasts about a day in the refrigerator. (Obviously it will be easier to judge once you’ve done it, but a little medium goes a long way.) You will want it thick enough to adhere to your stamps, but not so thick that you lose definition. If you’re silkscreening, you’ll want the thickness of silkscreen ink. Make some practice stamps before you commit to your fabric!

Mordant Printing

You can mix a mordant into your gum trag mixture. We used very small amounts of copper and iron, and a slightly less small amount of alum during our classes.

Gum trag with mordants

Here is a thread spool print with copper mordant:

Here I’ve printed on a silk scarf previously dipped in indigo with alum, using a feather for my print:

Here I’ve used an iron mordant on silk noil, again with feathers. I used an old paintbrush to apply the mordant mixture:

Discharge Printing

You can mix and acid or a base into your medium to discharge color on an already dyed piece.

Gum trag with soda ash

Here I tried using soda ash to shift the color on a pisolithus mushroom-dyed piece of silk:

Here I’ve used tartaric acid to discharge the logwood dye on silk organza:

You can do combinations of these techniques:

Discharging with a print block

And printing with an iron mordant

How to set your prints:

Lay out your dried fabric on an old cloth in a single layer, fold extra cloth over, and roll up, jelly roll style so that it will fit in your steamer basket. You want STEAM ONLY! Take care that the water is not getting into the bottom of the basket, and place a towel or piece of felt on top underneath the lid to keep condensed water from dripping back down. Make sure you’ve got steam going before placing your jelly roll in the steamer basket. Steam ten minutes, and remove carefully. Let cool until it’s comfortable to handle, then unroll.

Jelly roll in steamer basket

Wash your steamed fabric in warm, soapy water to get the gum trag residue out. It still contains mordant, discharge or dye, and if the excess isn’t washed out it will go into your dye pot and change the result.

Here are some results after dyeing our prints. The yellow is from onion skins, the pink from Brazilwood, and the orange a combo of both.

Here are my feathers. You can see that the gum trag wasn’t washed out completely by the extra dark muddiness around the onion skin feathers.

I decided to after-mordant the whole piece in alum, and not only did that get rid of the excess print fuzz, it changed the color of everything. It’s a bit 1970’s decor now, but I think it will still make a nice pillow:

For the discharge printing, you don’t necessarily have to steam the piece before washing. Here’s a sample of logwood on silk that I discharged by painting the back of a leaf with gum trag and citric acid, and then simply washing when I liked the result. It made a nice multi-colored effect:

I steamed my Ph-shifted fabric, and once I washed it out it ended up being merely discharged. I think I would have had better results if I’d washed it out as with the leaf print:

And here is a piece of silk crepe de chine that I silkscreened with alum and then dyed in Osage orange:

So, to answer your question Rachel, you have a lot of options. You can make a mordant print on unmordanted fabric. You can make a (different) mordant print on mordanted fabric. I didn’t include any photos, but you can mix natural dye extracts with your gum trag and print directly that way, with color. You can discharge already-dyed fabric. And you can do combinations of these techniques. You’ll no doubt have noticed that all these examples are on silk, but many of my classmates used this same technique on cellulose fibers.

There is also the option of surface design using natural pigments, which I’ll cover in my next post.

Fresh Leaf Indigo

 Sally Williams

 Blog

The hardest part about dyeing with fresh leaf indigo is growing the indigo. One of the people in my natural dyeing study group did all the hard work, and brought it in to share. This is what fresh Japanese indigo looks like:

Japanese indigo, persicaria tinctoria

The leaves are picked off the stems:

Then blended with ice water:

And strained through a cloth (in this case, silk):

We squeezed out the cloth to extract as much juice as possible, and this was our dye bath. We put our fiber in, a mix of wool, linen and silk:

Fresh indigo dye bath

We massaged the items in the bath occasionally, and let them sit in the bath about an hour. The bath began to oxide:

We then removed the items from the bath and let them air out. The color slowly changed from green to blue on silks, a pale green on linen, and a dark blue-green on wool. The oxidation time was much slower than with a reduced-indigo vat.

This is the silk straining cloth:

Straining cloth after several batches

Straining cloth after half an hour

Bonus round: we also used the leftover pulp from the straining cloth to “paint” on fabric— basically rubbing it into the fiber like a grass stain.

We let the pulp-prints dry and oxidize before rinsing. And although we did not do this step, here are instructions to precipitate out the indigo from a fresh bath, to use in a reduction vat. It’s a great teaching article using fresh woad.

Japanese indigo seeds are available from various places on line, and the plants like a warm, humid environment. Humid places can get several crops per season before the plants die. Places that are dry in the summer (like western Oregon) can get one crop during the growing season with irrigation.

How simple dye techniques can help bust your stash

 Rachel Wolcott

 Blog

This is the story of how a ball of pink mohair yarn, a bit of acid dye and a microwave helped me transform some long-forgotten yarn into exactly what I needed to knit the sweater I want.

Like many knitters, I have a lot of yarn bought in a fit of love at first sight, only to linger in a box for a few years. I keep telling myself it will all get used. Eventually.

When I was given a ball of hot pink mohair yarn last weekend, I thought: yes, I can use that and I think I have some yarn to go with it.

Turns out I had quite a few odd balls of mohair in my stash–green, grey, blue and light pink. I found this pattern on Ravelry and thought, that’s the one.

Belarus, by Kaffe Fassett

This pattern calls for nine colours. I had five–hot pink, light pink, green, grey and blue. My options were change the colour scheme set out in the pattern or dye the grey yarn I had to create four more colours.

Here I made some assumptions. The first was that the fiber content of the grey mohair would take the acid dye. It’s mohair, silk, nylon, polyester and metallic. I also assumed I could get good colours over-dyeing the pale grey yarn.

Selection of mohair yarn from my stash

Luckily those assumptions turned out to be correct . However if you want to dye commercial yarn in a colour that might not look nice over-dyed… I would definitely test first. Also make sure to check the fiber content of the yarn. Protein fibers–silk, wool–dye the best with acid dyes. Some synthetics take acid dyes too. Cottons and other plantern-based fibers (bamboo, hemp, linen etc) require different dyes completely.

Once I planned out which colours I was going to dye my grey yarn, I got out my microwave (one I use for dyeing), a scale, a ball winder, some glass jars, the dyes and some vinegar.

1. Thinking I wasn’t going to need a full 25g of yarn for every colour, I divided two balls into four using my ball winder and scale. I ended up with four balls roughly 12-13g each. It’s critical not to wind the yarn too tight or the dye won’t penetrate into the yarn closer to the centre of the ball.

2. Soak the yarn in warm water and a bit of white vinegar. Easy does it. You don’t want the yarn to felt or get into a knotted mess.

3. Get your dyes out and prepare them. For small quantities of yarn you will need very little dye powder. I probably used about 1g of dye per 12g ball I dyed. Put the dye in some warm water, stir and add a little vinegar.

I used Ashford’s purple and black dyes to get the purple and dark grey colours. For the wine colour I used Jacquard dyes’ russet and a very little Ashford navy blue. For the red I used Jacquard’s fire red.

Put the yarn in the dye. Make sure it’s not too crammed in there otherwise the yarn will dye unevenly.

Put the jar in the microwave for 2-3 minutes on high. Let it sit for 5 minutes or so, then give it another 2-3 minute blast. Let it sit and cool. If you haven’t overdone it on the dye, the water should be clear and the dye bath exhausted.

4. Carefully rinse the cooled yarn and squeeze out the excess liquid. Now let it dry.

I’m pleased with my results. The grey yarn took the dye nicely and the colours are close to the ones used in the sample. Sure they are not identical, but that isn’t an issue for me.

Nine colours ready to knit

Next yarn to be over dyed: the balls and balls of yellow wool my mother gave me a few years ago. Yellow really isn’t my colour, but I’m pretty sure I can make them into something I will like.

Fun with Cochineal

 Sally Williams

 Blog

After indigo, I bought a cochineal dyeing kit which contained the bugs, several mordants and some vague instructions. (I say the instructions were vague, but really they gave several options as far as time vs. temperature in mordanting. It’s one of those things that once you know what’s going on makes perfect sense.)

Rachel and I did a test run when she was here last April (Sheep Cabana retreat: dye as much stuff as possible in 48 hours), and here is what we came up with:

Cooking and straining some cochineal bugs

We started with 4oz of dried cochineal (which is a lot), cooked them for about an hour and then strained the liquid into the dye pot. I saved the used bugs for later. Then we mordanted our wool. We used some white Shetland and some grey mohair locks, and mordanted with both alum and tin, by simmering our fiber in each mordant bath for about an hour. I would say that our mordanting pots weren’t large enough, because the tin-mordanted wool definitely felted.

The dye pot, onion bag of mohair locks on top

We could have used a bigger pot.

Viola!

Here are the results, from top clockwise: tin mordanted wool, alum mordanted wool, alum mordanted mohair, iron after-mordanted wool, iron after-mordanted mohair.

Rachel left, and after a couple of months I got out the leftover cochineal bugs again and tried some more dyeing. (Those bugs sat on my patio in that plastic container, above, the whole time, ignored. I had no issues with them rotting or anything else unpleasant.) I re-simmered the bugs and left them sit overnight in the pot, and strained the bugs out in the morning. Then I did a series of successive dyeing on 50g each of alum and copper-mordanted wool:

Top, alum mordant
Bottom, copper mordant

I heated the cochineal dye pot, added the mordanted wool and let it sit out on the patio here either all day or overnight. The total hands-on time was probably 1/2 hour.

Here it is spun up:

Successive alum mordant, left to right, with copper mordant wound into a cake far right. The orange is the immediately adjacent cochineal overdyed with weld.

I’ve been taking some natural dyeing classes at the Oregon College of Art and Craft, and one of the neat things we did was dye with cochineal with no metal mordants. Instead we used 25% WOF of cochineal, 10% WOF powdered gallnuts (Gallic acid) and 10%WOF citric acid, all in the dye pot at once. Hot tip: we ground up the cochineal bugs and a little water with a mortar and pestle. No soaking required.

We simmered wool and silk noil for an hour and got these lovely colors. The cochineal strikes the wool and silk differently!

Shibori cochineal on wool

Left, wool, right, silk noil

These are nice colors on their own, but I also wanted to experiment with this dyeing method as a base color. Here is the same fabric overdyed with indigo. One of the very interesting things about cochineal is that the color will shift from red to blue, depending on Ph. The middle samples are overdyed with indigo (about Ph 12) and rinsed, the far right are the same, but rinsed in a white vinegar solution (about Ph 3).

Cochineal overdyed with indigo

I also tried some after-mordanting, with iron, copper and alum mordants:

Left, iron after-mordant
Middle, copper after-mordant
Right, alum after-mordant

There is really a lot you can do with these little bugs, and a huge range of color, depending on what techniques you use. In other words, fun!

Autumn Leaves and Contact Dyeing

 Sally Williams

 Uncategorized

Instructor’s sample of leaf contact dyeing

I had my first Natural Dyeing class at the Oregon College of Art and Craft last week. We started by walking the campus and collecting various autumn flora: fallen oak and maple leaves, pink-backed cherry leaves, fresh comfrey, spotted dying blackberry leaves, walnut hulls, tupelo, madrone and walnut leaves, Indian blood grass, and anything else that caught our eye. The ostensible purpose of this was to collect material to make our own contact dyed projects, but really it was to get us excited about natural dyeing. This time of year in the Pacific Northwest the ground is littered with dyestuffs, and the quick and easy method we learned yielded pattern as well as color.

Once we collected our leaves, we laid them out onto fabric or paper, and either rolled up our fabric tightly around a stick (or for added color, around a rusty iron nail) or accordion folded and clamped for a shibori effect. These packets are then simmered in a water bath for an hour, and then removed and unwrapped.

What I found most interesting about this technique is that there is really very little dye in individual leaves (for the most part tannic acids) but because of the wrapping or clamping, the color can’t migrate anywhere other than onto the fabric or paper. In other words, the opposite of leveling. In a lot of cases, the color transfer is more akin to printing— the fabric or paper is not really dyed per se, but stained or imprinted with the actual leaf color, giving pinks or greens which don’t exist as an actual dye. Our instructor cautioned us as much, saying that these colors will fade with washing or over time. That said, there definitely was dyeing of fabric around the periphery from the tannic acids, and also where the rusty nails provided an iron mordant.

Here is a leaf print where I had an iron plate clamped to the outside of my fabric packet:

Leaf print on silk noil with iron plate

And likewise wrapped around a large rusty nail:

Silk charmeuse leaf print wrapped around iron nail

Here is the difference of the dyestuffs on cellulose. For one, I didn’t get my packet wrapped tightly enough and the colors ran. For another, the yellows and greens remained printed while the tans of the tannic acids didn’t penetrate as much. I expect this to be a function of the density of the cellulose in paper form, and I would expect better tans on cotton yarn:

Wrapped leaf print on paper

This technique also led me to revisit my forays into dyeing with candy. I’d encountered poor results with a lot of candies that contained very little dye. So I tried some candy contact dyeing:

The candy melted pretty quickly, so it was hard to keep the fabric tight, but the dye migrated onto the fabric rather than into the dye pot. I can see some candy-related shibori in my future!

I’d also encountered some inexpensive pomegranates at the grocery store last week, and per Rachel’s last post I bought them for some seasonal dyeing. Pomegranates contain ellegic acid, which are yellow tannins, so I thought this would be a quick way to see what sort of coloring I could get from them:

This is one slice of pomegranate:

Folded and clamped pomegranate slice on silk charmeuse

And here is multiple slices and layers, with the rest of the pomegranate in the dye pot:

Folded and clamped pomegranate on silk noil, over some walnut hull spots

Tight wrapping and clamping is the key to good transfer, but whether you are preserving autumn leaves, testing dyestuff potential, or finding another use for seasonal candy, it’s such a quick and easy technique that it’s definitely worth trying.

Last of the summer dyes

 Rachel Wolcott

 Blog

Marigolds

Autumn has been a mellow affair. Trees are only starting to turn colour and drop leaves. Flowers continue to bloom and there is plenty of natural dye stuff still to be gathered. It’s time to get a basket and take a walk to find some dye stuff to try out now or over the winter.

Coreopsis

I’m drying dahlias, marigolds, calendula and coreopsis from my garden. Acorns and walnuts are both good for dyeing as are sumac leaves, rhubarb roots, carrot tops, willow leaves and bark, chrysanthemums and pine cones. Not all plants will give you color and some that do–especially berries–are not colourfast. Don’t waste your time dyeing with blackberries or beets, for example, because the colour will fade quickly.

Dahlias

Lichen is also an option, but not all lichens give a dye. Sally is planning an in depth post on lichen dyeing so I will just give a few pointers on lichen gathering and preparation. Do your homework before you go out to identify lichens that give a dye. If you’re not sure there is the bleach test. If the lichen turns red when treated with a drop of bleach it should give colour for dyeing. Here is a helpful link on lichen dyeing.

Personally I’ve had no luck with lichen. Any pointers are appreciated!

As Autumn becomes winter there won’t be as much dye stuff around. However ivy berries and leaves might be worth a try along with mahonia berries. And there is always the humble onion skin. It gives a beautiful golden color and is simple to find and use. Other household items that give color include pomegranates and avocados.

For those of you who need help identifying plants I suggest a book that has pictures and descriptions of plants local to you. As Sally found out it’s properly identifying plants and trees is pretty important.

I use River Cottage’s Hedgerow book for identification. Books like the Ashford Book of Dyeing and Jill Goodwin’s A Dyers’ Manual give a lot of information on what colors certain plants give and whether they are color fast.

One other project for the budding natural dyer is to grow your own dye plants. I’ve started madder this year, which I need to re-pot into a larger container. Other flowers like dahlias, marigolds and coreopsis have all given loads of lovely yellows and gold colors this year. They’re all easy to grow and inexpensive. If you have space you might also try woad, indigo, St John’s Wort and safflower. It’s easy to find seeds online or from another natural dyer.

On Mordanting

 Sally Williams

 Blog

Indigo is apparently the gateway drug of the natural dye world. It led me to try dyeing with cochineal, which should have led me to a better understanding of mordanting, except it didn’t. There are a lot of recipes, but not a fat lot of information out there on the science of natural dyeing. There is a lot of information on synthetic dyes. As it turns out, there is a good reason for this.

The history of synthetic dyes is also the history of organic chemistry, so the process of learning how to make synthetic dyes provided the chemical knowledge. The advent of synthetic dyes squeezed out the natural dyers’ guilds, so the new chemical knowledge wasn’t applied backward. There is a lot of good information out there on the invention of mauveine, the first analine dye. If you love history, how synthetic dyes changed the socio-economic world is fascinating, and it in part explains why there is precious little textile manufacturing still done in the US. Some of the more interesting monographs I’ve come across about the chemistry of natural dyeing are from India, Pakistan and Egypt, where there still are textile industries, and where scientists are taking another look at natural dyestuffs in order to have a more sustainable and less toxic impact on their environment. I’ve ended up learning about synthetic dyes, color chemistry, the quantum physics of color, synthetic fibers, and finally, mordanting and natural dyes.

That said, Maiwa and Turkey Red Journal are both excellent resources for natural dyeing information, including the chemistry, and they are both on the forefront of bringing the chemical knowledge back to the natural dye world.

So what is mordanting? If you are using metallic mordants, basically you are making your own acid dyes. Instead of using an acidic bath to promote ionic bonding as with synthetic acid dyes, the metal ions of the metal mordants have a similar polar effect. The mordants form covalent bonds with the color bearing compounds in the dyestuffs, which are the very strong bonds between atoms (sharing electrons in the outer shell). Since they are acid (polar) dyes, they therefore bond better with the positively charged amino acid chains (wool, silk) and poorly with cellulose (cotton, linen).

Tannic acid is a non-metal mordant, but “tannic acid” itself isn’t really a discreet chemical, but rather a broad heading under which several acids fall (which also happen to be tannins): Gallic acid, ellagic acid, and catechic acid. Most of the so-called “substantive” natural dyestuffs that require no mordanting have some form of tannic acid in them, for instance, sumac, pomegranate, fustic and cutch. Tannic acids bond well with protein fibers (think tanning hides), and also with cellulose plant materials. It also bonds well with the metal mordants, so plant fibers normally get pre-mordanted with tannic acid, and then again with the metal mordant.

I really wish I could tell you what chemical bonds are formed between tannic acids and these different fibers, but I’ve had no luck in finding scientific documentation thus far. I have to assume it’s not covalent bonding with cellulose just because fiber reactive synthetic dyes are so much more wash fast. I’m starting a natural dyeing class in October and I’m hoping to get to the bottom of this.

Nowadays aluminum acetate is available to mordant plant materials and the tannic acid step is debatable—this post and this post from Turkey Red Journal do comparisons of dyeing cotton cloth with different configurations of tannic acid/alum/aluminum acetate. Some of their considerations are cost and availability for dyers in poorer countries. Rachel does most of the cotton dyeing between the two of us, so I’m leaving it to her to take good notes on her findings.

This monograph is great in detailing the chemical structure of wool. There is a lot going on in a strand of wool, aside from the positively charged dye sites. There are other chemical bonds that give rise to it’s strength and elasticity, and these are both things that can be affected by Ph, heat, and specific properties of different metal mordants like iron or tin.

There is a time vs. temperature factor in mordanting. A lot of recipes call for simmering your wool in your mordant for an hour, but that can easily lead to felting. Heating up your mordant and letting your wool steep overnight can often produce a more thorough saturation of the fiber and therefore more even dye uptake. Mordanting can take place before, during, or after the dyeing, but if it’s done prior to adding the fiber to the dye pot, there is more control over the mordant-to-fiber ratio, and the mordant bath can continue to be reused. This becomes more important when using the more toxic of the metal mordants, tin, copper and chrome.

Older mordanting recipes called for an excess of the metal mordants to ensure good dye uptake, in part because the strength of the mordant material was not guaranteed. Now we can source mordants with guaranteed strength and purity, so we can be a lot more precise and use recipes that leave little to no extra mordant in the bath. I did some trials with cochineal earlier this summer (that’s the next blog post). Using a recipe for a weighed amount of fiber, I tested my mordant bath to see if it was actually discharged (my copper did not seem to be), by adding more fiber to the “discharged” mordant bath and then soaking it in the dye bath and seeing if the dye strikes or not. When I was done I bottled up and saved my remaining mordant bath rather than tossing it out anywhere.

On hold for the next round of mordanting

Once the mordant has bonded to the fiber it’s not going anywhere, so you can use different mordanted materials in the same dye pot, which is fun and interesting because you can see the effect the different mordants have.

Some metal mordants are toxic. Chromate poisoning is particularly unpleasant. Oxalic acid, often used to shift colors as an after-mordant is toxic. Synthetic “true black” acid dye is also toxic, as it contains chromium as it’s coloring component. None of theses things belong in the groundwater, or your septic tank, or near kids, pets or livestock. Entrapment is the state wherein metal particles are trapped in the steam from a water bath, and are then able to be inhaled, so don’t mordant in your kitchen. And for that matter…

Oak galls

A cautionary tale: we have a large tanoak tree growing next to the abandoned well out by our barn, and as a good source of natural tannins, I checked the interwebs for what the tannin concentration should be compared to oak galls, etc, for a possible recipe. What I found was that it wasn’t a tanoak. So I used a tree identification website rather than the book with illustrations I’d used initially, and the final question on the flowchart was “do the leaves smell like almonds when crushed?” Ironically as it turns out, this reminded me of the opening lines of Love in the Time of Cholera. My tree does smells like almonds when the leaves are crushed. It’s a cherry laurel, and when you boil the leaves you get hydrogen cyanide, which Nero used to poison his enemies’ wells. So. Back to collecting gall nuts.

The Science of Dyeing

 Sally Williams

 Blog

What is color? When I studied philosophy as an undergrad, it was always treated as a “secondary quality”, that is, something that’s not intrinsic to the nature of the thing itself. And while it’s true that how we see color is a subjective function of our eyes and processing in our brains, the colors of things is entirely dependent on the physical makeup of those things. When we see color, we are seeing into the atomic and subatomic nature of things. In other words, a tree is green in a forest even if no one’s around.

To understand how color works, you need a little quantum physics. This monograph on color chemistry is concise, well-written, and with a little patience, accessible even for people like me who have only high school level chemistry and physics. If you are at all interested in how dyeing works, it explains everything.

I’m also slogging through this one. It’s highly technical and I can only digest a few pages at a time, but it details all the general information in the first book. If you want more after reading The Chemical History of Color, then this is for you.

To very generally sum up, the visible spectrum that our eyes can detect takes place in a really small range of wavelengths, from red to violet. Everything of shorter wavelength then the red range is the infrared, and everything longer than the violet is the ultraviolet. How these wavelength are generated or influenced happens at the quantum level, with the interactions of the electrons within an atom or a molecule. The electrons need to be understood as waves, not particles as I learned in high school chemistry. There are four or five different models that explain wavelength production, depending on the arrangement of electrons in their shells around the nucleus, and how they combine, or don’t combine with other atoms. What’s neat about all of this is that our eyes are seeing what’s going on at the quantum level! (That’s my take on it. I can’t think of any good reason why humans spend so much time and effort changing the color of things, if not to influence the building blocks of the world itself.)

Natural dyeing shows us that there are some plants and insects that impart good, lasting color, and some that are fugitive. The beginning attempts at synthesizing these color compounds were all trial and error, but now computer modeling can predict what wavelengths a particular molecular configuration should yield, and how to bind it to a particular fiber. It should be noted that two things dyers care about, light-fastness and wash-fastness are two separate issues. Light-fastness depends on the ultra-violet spectrums’s influence, whereas wash-fastness depends on the type of bond with the fiber (for the most part). Ultraviolet wavelengths can greatly influence the visible spectrum. We see this when colors fade in the sunlight. This often comes into play in natural dyeing (with black beans and berries for example)…one of the advantages of synthetic dyes is that they’ve been designed to be less susceptible to this effect. Another advantage of synthetic dyes is their leveling ability, that is, to dye evenly. They’ve been designed to bond weakly with the fiber so that they can actually un-bond and re-bond, rather than strike all at once in a concentrated area. Some of the molecules used to produce color are quite large, especially in the blue range. This is why even when using an acid dye, there is still blue left in the dye bath even though it is fully exhausted. The color producing part of the molecule is so large that it will actually break off from the part that bonds to the fiber during the leveling process. One of the mysteries of indigo is how it’s able to produce a blue color out of a relatively small molecule (there are several theories).

Synthetic dyes are often described as brighter than their natural counterparts. This is because the synthetic dye molecule is emitting a vary narrow, specific wavelength, where a natural dyestuff, as a complex plant material, is emitting a broader range of wavelengths within that color band. Different mordants also affect the color in natural dyeing. The metals used in mordanting not only have the necessary number of electrons in their outer shells to form covalent bonds with the dyestuffs, but of themselves have different wavelength properties…precisely because of how the electrons are composed around the nucleus of the atom. (This website/app of the periodic table is great. It shows everything you might want to know about each element, down to the electron spins in each orbit.)

Color aside, to understand how dyeing works, you need chemistry: the chemistry of the fiber being dyed, and the chemistry of the dye. Here are two excellent blogs that explain the chemistry of synthetic dyeing in simple terms:

Gnomespun Yarns

Paula Burch’s All About Hand Dyeing

Again to sum up, there are different types of bonds that can be formed, and they depend entirely on what you are dyeing: the amino acid chains of proteins, or hydroxide chains of cellulose plant material, maybe a mixture of both in the case of synthetic fibers, (or none of these in the case of polyesters). Animal fibers have positively charged receptor sites, so ionic bonding occurs with acid dyes (and also some hydrogen bonding, which is like ionic bonding but smaller). Plant material’s OH hydroxide chains don’t have the positve charge sites that animal fibers do, so fiber reactive dyes are designed to form covalent bonds, which are very strong, in a basic, rather than acidic bath. Disperse dyes dye plastics at high temperatures and pressures, although there are disperse dyes available for the home dyer that work in the dryer. Direct dyes work through a force called substantivity, and they need to be rather large molecules in order for this force to work. Since they are so large they are not particularly wash fast, and the colors are often duller. They are generally used on plant fibers, and are a component of all-purpose dyes like Rit.

This post by Gnomespun Yarns does a good job explaining the difference between animal fibers and plant fibers, and how it affects dyeing. This one by Paula Burch does a good job explaining the different types of chemical bonds that are made with the various types of synthetic dyes. They are both well written, with nice diagrams, and really explain why it’s important to know the chemistry of what you’re trying to accomplish.

All of this is by way of the next blog post, which is about mordanting. The chemistry of natural dyeing is only very recently becoming well documented, and I’ve found that understanding the technology that succeeds it is the most straightforward way of getting to it’s precursor.

But is it yarn?

 Rachel Wolcott

 Blog

Art yarn?

Ah the allure of Art Yarn. Behold its super-chunky sparkle, its beads, its coils and luscious locks. Resistance is futile. Or is it?

When I started to spin I announced to Sal that all I wanted to make was art yarn. I probably told her I wanted to explore colour and texture. I was making it up.

Sal told me something like this: If you’re ever planning to make anything like a sweater or a wearable garment you should think about making less-arty yarn.

She had a point.

These days I think about hand spun yarn completely differently. What I used to consider art yarn, I now classify as novelty yarn.

Most of the time I’m experimenting with new materials and techniques. I’m spinning to weave or to knit. My use of art yarn is sparse. That’s partly thanks to my fairly boring sartorial habits. Sal tells me that’s a trend now! Yay!

So what about art yarn?

Last month Alison Daykin gave my guild a talk on art yarn (see below). Beforehand I was curious what she would have to say and it got me thinking. What is art yarn? Is it yarn for yarn’s sake? Is it a novelty item? Does anyone actually use it?

I still make a lot of art yarn, but I call it handspun. Like most spinners I’m experimenting with colour, texture and gauge. Most of it isn’t sparkly or bejeweled. The excitement is in the color or the materials.

Here’s some sport weight yarn I made for a weaving project.

Blue yarn

The blue colorway is a combination of natural coloured and dyed fleece.

The red is a blend of acid and natural-dyed fleece as well as natural coloured. To me these are rich in colour and texture. I’ve made little aesthetic decisions throughout the making process.

Red yarn

Is it art or is it yarn?

These are some examples of what are more commonly considered to be art yarn. There are the dyed locks, the thick/thin look and some bouclé-like yarn.

Bouclé, sort of

Thick thin

Yarn or art? Both?

Lexi Boeger sees it this way: “I believe the onus is on the buyer to look at the yarn and be able to determine an appropriate project to use it for. This puts more work on the buyer, but ultimately it will make that person also more creative..” (See Spinartiste)

Boeger goes on to say that art yarn can help the knitter (or weaver for that matter) think beyond the pattern and become a designer. My reading of that is: art yarn can be a starting point. It asks the question: what can you make with me?

It’s worth pointing out that Lexi Boeger isn’t making art yarn anymore.

Locks

JazzTurtle has a long list of patterns that can use art yarn. But to me art yarn is perfect for weaving–especially saori weaving, which is all about experimentation and personal expression. It’s not really concerned with pattern or convention.

This saori-inspired piece uses some art yarn. For me this piece was a big departure from the norm. Here are colours and textures far from my comfort zone. It marks a step in a creative journey, but I’m not sure the path ends at art yarn.

Weaving with art yarn

[Sal here. I’m going to horn in on your post for a minute]

I would argue that handspinning is technology, and as such there is an intrinsically practical component to the resulting product. Some yarns take a good deal of skill to make well (bouclé for example), or have aesthetic consideration in their colors or textures (as yours do above), and this intersection of technical skill and aesthetic consideration I would call “craft”. Calling something “art yarn” is almost oxymoronic. Yarn for yarn’s sake, as you say, really makes no sense— like building a chair that you can’t sit on. But I know plenty of people who spin and never do anything with the yarn because they don’t knit or crochet or weave, and are perfectly happy that way. I suppose there is a Venn diagram we could make that shows the people who like to build chairs, but don’t actually sit down. I think one could certainly make yarn that’s an end in and of itself, and it could be considered art instead of artisanal, but I think the intention behind it is key, because it would be subverting the concept of yarn. The rest, as you say, is novelty yarn. I’m curious what your guild speaker had to say on the subject. And if they have any good patterns.

[Now back to our regularly scheduled blog post ;)]

Fancy Yarn and permission to spin

When Alison Daykin came down from Derbyshire to talk to the Mid-Essex Guild about art yarn, like Sal I was curious what she had to say about art yarn. One reason for that curiosity was I suspected [knew] many guild members were dubious of art yarn. Many–not all–take the view that art yarn is what you make when first learning to spin. “Don’t worry,” they tell new spinners. “You’ve just made art yarn!” And then everyone laughs.

Alison Daykin described what she makes as fancy yarn, not art yarn. Fancy yarn, Alison explained was any kind of yarn you made that’s non-standard–core spun, bouclé, crepe, thick/thin–that has some irregularity in the making. That irregularity could be introduced in any or all of the steps for making yarn: prepping fiber, color blending, spinning and finishing.

According to Alison, fancy yarn isn’t anything new, in fact Mabel Ross, author of The Encyclopedia of Handspinning, was an early advocate of fancy yarn. However, when Alison started spinning in the late 80s/early 90s she felt spinning non-standard or fancy yarn was discouraged. She was taught that the point of spinning was to churn out yards and yards of yarn that looked like it had been made in a mill.

“I wanted to make different yarn and I felt inferior, because I didn’t want to spin plain yarn,” she said. But after taking a course on spinning and dyeing for tapestry weaving from Bobbie Cox, Alison felt she had, “Permission to spin whatever I wanted. Once you know the rules, you can break them.”

Art yarn, Alison said, is a term that grew out of a trend of making yarn out of recycled materials like plastic bags and cassette tape. She did not see the point in putting yarn in a bowl or hanging it up to admire.

“If I can’t use the yarn, then I’ve wasted my time. Use it to make a garment look different. If you use a little yarn in a piece, it can look lovely. Art yarn has got to be practical as well as beautiful,” she added.

Natural dyeing with cotton

 Rachel Wolcott

 Blog

left to right: onion skins, madder, indigo on organic cotton yarn

It’s funny what can get you off and running on a project. Dyeing cotton really wasn’t on my to-do list until I read an article in the Winter 2015 Spin Off where Dye-lishus premordanted cotton sliver was tested and reviewed. My first thought was, what’s the fuss with cotton that would make premordanted sliver desirable? Would it make dyeing easier?

One of the things the Dye-lishus premordanted cotton sliver apparently can do, which home mordanting can’t, is allow the fiber to take acid dyes, which are made for dyeing protein fiber (wool, silk, etc). Dye-lishus’s USP is: you can dye this fiber with anything–acid dye, food colouring, procion dyes–and it will stick.

However, my interest in mordanting my own cotton was stronger than my desire to try out the Dye-lishus fiber. Another day perhaps.

A quick internet search informed me that mordanting cotton for natural dyeing is a two- to three-step process, depending on the kind of cotton used. It’s not complicated. It’s not particularly labor intensive. It’s just one or two more steps than mordanting wool.

There are some important things you should know before mordanting and naturally dyeing cotton.

* Cotton is mordanted with tannic acid, then aluminium acetate. Those are different mordants than the ones used for wool. Both are available from natural dye suppliers.

* Depending on what kind of cotton you’re going to dye, you may want to scour the yarn or sliver. I washed my yarn in very hot water with soda crystals. If you’re using organic cotton, don’t bother with this step.

As with all aspects of natural dyeing–on cotton, wool or otherwise–there are many recipes. I used the simplest one I could find, which happened to be on the Wild Colours site. It has lots of information on natural dyes and mordants.

I used 10 percent of weight of goods (WOG). To mordant 100 grams of fiber and yarn, I used 10 grams of tannic acid and 10 grams of aluminium acetate. It’s worth getting a digital scale to weigh the mordants. Put a clean yogurt pot on the scale, zero it, then tip in your mordant.

Soak your fiber/yarn for a good hour before adding it to a dye pot in which you have dissolved 10 grams of tannic acid. You want there to be enough hot water to cover the fiber and give it a bit of room. No need to heat the pot, just leave it until you’re ready for the next step. I left mine overnight.

Repeat the process, but this time dissolve 10 grams of aluminium acetate and then add your wetted down fiber. Again, you need hot water to dissolve the aluminium acetate, but you don’t need to heat the pot. I left mine to soak overnight in a bucket.

When ready to dye the fiber, make sure to rinse it well to get out any mordant that hasn’t attached to the fiber. Do it now or it makes the fiber a bit chalky after dyeing. Otherwise make sure to rinse your fiber well after dyeing.

I dyed with madder and onion skins, because that’s what I had to hand. I soaked the madder root in hot water overnight. I used 50 percent WOG of madder. Onion skins are very generous in terms of dye yield. I used a few handfuls and that was plenty.

cotton yarn, madder dye bath

Give the madder about an hour to simmer. I strained the root into a jelly bag, which I then returned to the dye pot. It saves you having to pick out little bits of madder from the fiber and makes sure you’re getting your money’s worth from the dyestuff. I fished out the onionskins with a slotted spoon put them in the compost.

Once the fiber was in the dye pots I left them to simmer for about an hour. I then removed them from the heat and left them to cool.

Dye baths made with natural dye stuffs do not exhaust the way acid dye baths do. That means there will appear to be a lot of color left in the dye pot. With acid dyes, you know the dye bath is exhausted when the water is clear. That doesn’t happen with most natural dye stuffs.

madder on cotton sliver

top: cotton sliver, bottom: cotton yarn with onion skins

Rinse your fiber well and leave to dry.

Last, but not remotely least, cotton can be dyed naturally without any mordanting or pretreatment whatsoever. Just make an indigo vat, following Sal’s fabulous fruit vat instructions. Indigo is a substantive dye–like walnuts and lichen–and does not require any mordanting process. Just look at it. Beautiful!

Indigo on cotton yarn (top), wool (middle), sea cell (bottom)