This semester I was granted an independent study, wherein I was able to further my exploration from BA of pigments from nature. We ordered both the beginner's colour kit and the indigo kit from Aurora Silk. The beginner's kit includes logwood, brazilwood, and fusticwood, which naturally generate purple/black, red, and yellow dyes, respectively. It also includes Iron mordant, which can be used to darken each of these colours to grey, burgundy or plum, and green, respectively, and alum mordant, which acts as a binder and makes fabrics more colourfast. The indigo kit includes supplies to make and refresh a vat of indigo dye, which can be used indefinitely. I also made a black bean dye, which was something I'd wanted to try considering it seems an unlikely colour source. It makes a blue dye, which is an otherwise fairly elusive colour.
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| colour kit (photo from aurora silk) |
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| indigo kit (photo from aurora silk) |
Most of my previous work with dyes were paintings, not garments, and therefore never needed to be rinsed, so colorfastness wasn't a big issue. With these kits, I was dyeing mostly fabric samples, although I did buy a couple of shirts and brought a pair of shoes to paint as well, so colorfastness is an advantage. Fabrics dyed in indigo do not need to be pretreated, since iron mordant is the only compound that will alter indigo. For all the fabrics that would be used with the other dyes, I prepared an alum mordant bath. It can usually also be added to dyebaths, but I just heated the fabrics in the alum mordant initially, and then stored them in the solution until I was ready to dye them. I used a few different kinds of fabrics: the kits came with lengths of silk, natural cottons, raw silks, and a sample of wool, and then I also bought 100% cotton t-shirts and a length of cotton muslin. Preparing the fabrics was one of the first steps, since obviously I can't do much with them until that part is done.
The other crucial first step was getting the indigo bath going. I didn't realise this about indigo before starting the project, but it is nothing like other dyes. In fact, it's a lot more like beer than like dye. It has to be mixed and left to ferment, for about a week, before it becomes a colorfast dye, and must be kept in the right conditions to ferment properly. Unlike other dyes, which are usually made simply by adding water to organic matter and letting it soak or heating it to extract colour, indigo requires several ingredients. Madder roots (which can actually be used in and of themselves to produce red and orange dye, but in this case serve a different purpose) contains an enzyme that facilitates the fermentation of the dyebath; basically they're acting as a yeast. In order to allow the indigo to penetrate the fabric rather than just affecting the surface, it must be dissolved in by alkali, for which washing soda, or soda ash, is used. Just as yeast needs sugar to ferment beer, the madder root needs some kind of food to ferment the indigo dyebath. For this, wheat bran is used. All the ingredients were premeasured in the kit and just needed to be combined and added to water.
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| Ingredients of indigo before being mixed |
The amount of dye was determined mostly by the size of the pot (guidelines are given) because a fermenting indigo dyebath should be exposed to air as little as possible. This meant I had to fill the pot until almost full, and as you can see in the photos of my setup, because the pot had a domed lid, I also kept it covered with a garbage bag to reduce the amount of air on the surface. While fermenting, an indigo dyebath also needs to be kept warm, ideally between 100-120 degrees. I didn't have a thermometre to measure the temperature, but the instructions suggest using heatlamps in the same fashion as they would be used to regulate a reptile habitat, and to aim for a temperature similar to warm milk for a baby. The danger in keeping the pot too warm is that the heat will kill the fermentation process and the dyebath will not turn out properly. I kept my pot on a hotplate on the "warm" setting for most of the week, which kept the pot itself at a temperature that was comfortable to the touch. For the first few days, I was concerned about safety, and opted not to leave the hotplate on while unattended, so it was turned off overnight (and I may have forgotten to turn it back on until the afternoon a couple of times). After the first couple of days though, I was more confident in the hot plate's ability to regulate its temperature and just left it on 24/7 until I was done with the indigo.
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| Logwood with and without water |
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| Fusticwood with water |
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Logwood dye goes on orange-brown
and gradually darkens to purple |
Meanwhile, the wood dyes took simple preparation. The brazilwood didn't require the same preparatory steps as the logwood and fusticwood, but I did this for all three anyways: I added just enough water to them to cover the mulch, let them sit overnight, strained them the next day, and repeated this two or three times before finally removing the mulch and adding enough water to the extract to allow the fabric to be submerged freely. Instantly, the logwood mulch tints the water a vibrant pinkish orange, and the fusticwood, as would be expected, a yellowish orange. I separated some of the extract from the first round of soaking to use as dye for painting, and stored this in mason jars. Having a smaller container of each colour also gave me an opportunity to experiment with iron mordant.
One thing I noticed when I first set up the brazilwood and especially the logwood dyebaths is that these colours don't necessarily look they way you would expect them to immediately. At first I was concerned, because I was very excited about the prospect of logwood producing purple dye. However, it just looked red orange. I then realised that it must be similar to indigo in the sense that it requires oxygenation, as you can see when I add water:
Brazilwood behaves similarly. This was also evident when painting: on first application to the fabric, the logwood dye appears orangey-brown. It takes a minute before it turns purple, and it gradually darkens over time.
This phenomenon became a small pleasure for me during this project,
and I made several people watch me perform this small but delightful chemical reaction.
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| my setup: hot plates supply heat to the active dye baths; extracts waiting for use are stored in roasting pans. On the left, the indigo ferments while plastic keeps it from being exposed to too much air. |
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| Small batches of a wider variety of colours, which I later used as paint-on dye: left to right: blue from black beans, plum from brazilwood with iron mordant, green from fusticwood with iron mordant, pure logwood purple, and pure brazilwood red. |
Iron mordant allowed me to make multiple colours from my four original dyes. I opted to paint the tartan I designed last semester in BA onto the shirts I bought, and for this I needed purple, dark green, and dark red. I had to experiment a little bit to get the right shades. Initially I was suprised by how much of a difference such a small amount of iron mordant makes. The difference between fusticwood yellow and a dark olive green is as little as 1/4 teaspoon.
When experimenting with brazilwood and iron mordant, I initially unintentionally made a very dark plum by adding too much at first. On the next back, I scaled back, and ended up with three varieties on a spectrum of red. I didn't add iron mordant to any of the logwood dye. In the instructions, it was described as a smoky grey, and I wasn't particularly interested in this colour. I had also already run out of jars. However, the olive green of the fustiwood wasn't quite right for the tartan design, so I ended up mixing up a separate batch of it and added some of the black bean blue. Ultimately I ended up painting with several layers of yellows, greens, and blues, to get the right shade.
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| Silk in brazilwood bath |
Dyeing with the wood dyes was fairly straightforward; it's the usual add fabric to dyebath, heat and stir, then rinse. One unanticipated result, however, was the potency of the logwood dye. With the paint-on logwood, I had little control over how dark the resulting fabric was because it's not a matter of time, it's basically just layering. Because that dye was cold, the colour was also not as intense. But with the heated dyebath, I learned that it takes very little time to achieve a rich dark purple. I put a piece of silk in the logwood bath at the same time as I put one in the brazilwood bath, and I figured they each probably needed, at the very least, ten minutes or so. After letting them simmer for a while, I removed the silk from the logwood bath, and it looked basically black. I figured, it may just be because it's wet, and it might dry to a dark purple. I left the red in for a little bit longer. As the logwood silk dried, it didn't appear to change colour. I figured, if it were still damp, it might at least dry to a black with a purply sheen. It is still basically black, however, and if there is any sheen, it is a very dark brown. I removed the red when it reached a rich crimson. I realised mostly through this exercise, that silk is probably the most colourfast material available, as it really took the dye well. Of course it dries a little bit lighter than it appears when you first remove it from the dyebath, but the difference was not overwhelming.
I'm not 100% sure what went wrong with the indigo dyebath, but I suspect it wasn't quite how it should have been. About a week after I had mixed it and left it to ferment, it developed spots of the coppery sheen described as one of the signs of a ready-to-use dyebath, however this film was not uniform like it should have been. I suspect either there was still too much air on the surface somehow, or more likely, the heat was not correct. Either it was too hot and this disrupted the fermentation process, or it was not quite warm enough and simply needed more time. The downside of doing this as a school project is that I have to have deadlines, so I felt I had to use the indigo dye whether it was 100% ready or not. I dyed two lengths of silk, and while they seem relatively colourfast, I was unable to achieve anything darker than a middle-value. Both lengths came out more or less the same value, even though I dipped one of them one or two more times than the other one. This is the other reason I suspect the dyebath was not quite prepared correctly. These two lengths of silk were some of the last things I dyed, so their lightness was also the result of a somewhat depleted dyebath. I also attempted some Japanese shibori techniques. Indigo was one of the main dyes in use in Japan until the 20th century, and shibori techniques have been used since as early as the 8th century. I attempted two techniques: pressing folded fabric between wood blocks, and winding fabric around a stick and then binding with string.
I really like how these turned out. Ideally these are done with silk, but as I had a limited amount of silk and it's difficult to find, I used some of my white muslin for this. These were a couple of the first things I dyed in the indigo, so the result was a bit darker than the silk lengths. Since they're bound, they also don't run the risk of trapping air as they're submerged, and therefore weren't as difficult to dye. You must be very careful, particularly while dyeing loose fabric, not to introduce air into the dyebath, as this will oxygenate the whole bath and ruin the colourfastness of the dye. I think this also happened when I was dyeing the silks, before I realised it's easier to lower it into the bath as a length of fabric than as a bundle.
Similarly to the brazilwood and logwood dyes, indigo does not appear blue at first. The liquid is actually green, and dyed fabric appears green or even neon yellow when it first emerges (mine was closer to a teal because my dyebath was not quite right). Here you can see the difference between a dyed length of silk that has sit for a while in the air and one that I've just pulled out of the dyebath. Although they dried to a fairly light blue (and I was hoping for a very dark indigo from the second one), I still can't get over how beautiful they are simply due to the sheen of the silk and the subtle inconsistencies in the colour from floating or touching the bottom of the vat while being dyed.
