Wednesday, July 12, 2006

Hand-dyed Studio pt. I: A Primer on Production

When you see skeins of hand-dyed yarns, it’s easy to get lost in all the glorious colors and textures.

But learning a bit more about the various techniques used to create those glorious colors can pay big dividends when it comes time to use them.

Commercially Dyed Yarn

When yarn is produced by a manufacturer (i.e., big company) rather than an artisan, it must be dyed on a large scale in order to be cost-effective. If a yarn requires too much individual handling when it’s being dyed, the price will increase and the yarn may end up being too expensive for most knitters to buy. Big companies are interested in volume of sales, so they have to produce their yarn in volume, too. So when big companies dye their yarns, they do it on a big scale: not a hank at a time but many pounds of fiber at a time.

There is a category of yarns that are called extruded yarns. The fiber is chopped up or liquified and extruded into tubes: think about those Play-Doh machines that little kids use to make “spaghetti.” Fibers like tencel and soy silk are made this way. Extruded fibers can be dyed as the fiber is being made; in addition to soy silk or whatever material the yarn is made of, pigment is added so that the fiber is extruded in its already-colored form.

The kind of yarns that are spun at a mill (like our beloved wool) are commercially dyed, after they’re spun, in large batches. The most obvious way is to dip large amounts of the fiber into vats full of dye (sometimes called dip-dyeing). This creates a solid color yarn. You may have seen multicolored yarns advertised as space-dyed: this involves applying different colors along the strands of yarn. Lisa’s going to talk about repeats in another post, but when we talk about a repeat, we’re talking about the order of colors that appear on a strand. Space-dyed yarns try to replicate the multicolored effects of handpainted yarns, but on a cheaper and more uniform scale. Finally, there’s a whole category of yarns called self-patterning: these are those cool sock yarns that make their own patterns – stripes or fair isle or jacquard -- as you knit them. Self-patterning yarns are made by winding the yarn onto plates; the design is mechanically printed onto the yarn, then the yarn is wound off, washed and reskeined.

Regardless of the technique, these yarns are mass-produced. This makes them more economical, but it also makes them more cookie-cutter. There is an emphasis on uniformity so that all of the yarn dyed in the same batch (or dye lot) is interchangeable. Skeins need to be virtually identical to each other within the same dye lot; they also need to be as close as possible to other dye lots of the same shade, for consistency’s sake. (And as you no doubt have realized, after having if you’ve ever had to mix dye lots, some manufacturers are more consistent than others.)

Hand-dyed yarns

When you are looking at yarns dyed by hand, however, all of this changes. There are different methods of applying the dye to the yarn (and I’ll talk about some later), but regardless of the technique, the yarn is done in small batches, with the dye applied by hand – not machine – to the yarn. Dyeing the yarn in small quantities means that you get very individualized batches; even skeins dyed at the same time, in the same dye bath, can come out surprisingly different. Applying the dye by hand enables the artisan to use more colors within the same skein of yarn, and to use more diverse ways of applying the dye to the yarn. And because the emphasis isn’t on producing a large quantity of the same color or creating uniformity among batches, the artisan has greater freedom to experiment with color, technique and style.

Asking a dyer how she dyes her yarn is a little like asking Mrs. Fields for her cookie recipe: she's not going to give it to you since it's her bread and butter (to mix food metaphors). But individual idosyncrasies aside, there are some common techniques.

The first thing that the dyer has to do is wet the fiber. Dyers may simply soak their fiber in water, they may use a wetting agent to help the fiber soak up water evenly, they may use an agent like vinegar to make the fiber more or less acidic, or they may use detergent to get rid of oils and other dirt. But before the fiber can be dyed, it usually needs to be wet.

After wetting the fiber and wringing it out, the dyer chooses how to apply her dye. She might dunk the skein(s) in some kind of receptacle full of dye bath: this is called immersion dyeing (because you immerse the skein in the dye bath). Immersion dyeing usually produce tonal effects, like “nearly solids” in which the color stays more or less the same and gets deeper and lighter.; but there are some dyers who dip-dye their skeins at different points along the skein (I have no personal knowledge, but I'm guessing Socks That Rock and Lorna's Laces do some variation on this).

Another method involves laying out the fiber and applying the dye to it as it’s laid out. This is what most people think of when they refer to handpainting yarn. Some people actually apply yarn to the individual strand with a brush; others use squirt bottles or pour dye directly onto the fiber. This is where individual techniques vary. You can apply dye very carefully and in a controlled way; you can overlap colors and see what happens (often brown); you can fling droplets of dye to get splotches (one reference book calls this the “Jackson Pollack” technique); and so on. The key is that the yarn is applied by hand, not machine.

After applying the dye, some sort of mordant must be used. A mordant is the substance used to set the dye (otherwise the color is likely to wash right out). Different fibers and different dyes require different mordants. Unsweetened drink mixes, like Kool-Aid, are popular for experimenting with because the high level of citric acid (vitamin C) acts as a mordant when combined with heat and used on animal (protein-based) fibers. Other dyes require substances like soda ash or alum as mordants. Some dyes require heat to set (some people put their Kool-Aid-dyed yarn in the microwave!) while others can set without heat.

After the yarn is mordanted (and if applicable, cooled), it must be rinsed. Again, individual preferences determine how the dyer washes the fiber: some use detergents, some use rinses like Eucalan, some use water alone. Many dyers like to see the dye exhaust, meaning bond to the fiber so completely that none is left to rinse out at the end. This is both cost-effective -- the dye is being used, not washed away -- and also better for the environment as you are not discharging dye into the sewage system. However, there are dyers who play with different effects and don't worry so much about complete dye exhaustion.

Last step: the yarn is then wrung and air-dried, and if necessary, put into balls or skeins for sale.

A note on chemistry

Different kinds of fibers need to be dyed in different ways. My high-school chemistry is long lost to me (chemistry-teacher father notwithstanding!) but for our purposes, all you have to remember is that different fibers (cotton, wool, silk, nylon) come from different sources (plants, animal fleece, worms, petrochemicals) and they need to be dyed in different ways. Certain dyes, certain techniques, certain temperatures and certain mordants will work on some fibers but not on others. I remember several years ago, after having great luck using Kool-Aid to dye wool yarn, trying a sort of tie-dye experiment on cotton T-shirts with my oldest kid. We used Kool-Aid but all our wonderful effects washed away as we rinsed. Lesson learned: the Kool-Aid technique won’t work on cotton or other plant-derived fibers.

In recent years there has also been a growing interest in botanical dyes, derived from herbs, flowers and other “natural” substances. Botanical dyes can produce wonderful colors and lovely effects. Marigolds, madder and other plants produce vivid dyes and can challenge a dyer because the same dye can produce strikingly different colors when handled differently. There are lovely books which discuss various botanical dyes and how to use them; just be aware that botanical dyes can sometimes require the use of strong mordants that may cancel out the environmentally-friendly aspects of the dye.

2 comments:

Liz K. said...

Fascinating lesson from the Black Bunny herself. I am really looking forward to this whole series, and really wish I could attend your hand-dye-o-rama at Rosie's. Alas, company's in town. Damn family!

ELL said...

Actually, Lorna's Laces doesn't dip dye the yarn. They open the studio once a year to members of the Chicago Knitting Guild and demo the process.

There are interesting photos here from the 2003 trip
http://www.chicknits.com/blog030620.shtml