Fiber preparation is not one of the sexy parts of dyeing, but it’s a process that can improve your results significantly. It’s kind of like painting the walls in your house. You can skip the prep and go straight to the paint, but then you’ll probably spend the next two years noticing the hair and cobwebs you painted over, and finding little spots starting to peel. Like dyeing, doing a good job of prepping to paint is likely to take longer than the fun color part, but spending the extra time really does get you noticeably better results that last.
So, I spent the last two days in my studio scouring cotton and linen. Scouring is one of the topics where I get most questions from my students. That’s largely because there isn’t time to scour in a day-long dye class, and still have time to learn about resists and dyeing.
What do you mean by “scouring”?
If the term is new to you, scouring is an intensive cleaning process that ensures your fabric or fiber is ready to take dye evenly and without any surprise reactions that might happen if there are chemicals you weren’t expecting in your fabric. Scouring cellulose fibers like cotton, linen, and bamboo is different from scouring protein fibers like silk and wool. I’ll cover protein fibers in a future post. For cellulose fibers, scouring involves simmering the fiber in a solution of detergent and soda ash. I use Orvus paste for this process because it washes out clean and does not affect the pH going forward. You can buy Orvus on Amazon or at many quilt and yarn shops, but the cheapest way I’ve found to get it is to buy at a feed and seed store. It’s also used to wash horses, and at my local feed and seed, it cost $10 less than on Amazon.
Do I really need to scour my fabric before dyeing?
You can absolutely dye without scouring first, but you may not like the outcome. New yardage and garments come with sizing in the fabric to keep them looking nice until they sell. If you are purchasing fabric online from a vendor that sells fabric by weight instead of yardage, they may also add starch to the fabric so that it weighs more. There may be chemicals or residue from the whitening process, too. I start by running the items through the laundry with Tide and no other fabric products like softener. I know people use a lot of different things on their laundry, and many of them will work just fine. I used to use Molly’s Suds until it got crazy expensive. A couple of things I do not recommend are vinegar and chlorine bleach. The bleach can leave residue in your fabric that may cause unintended and unwanted chemical reactions in the dye process. The vinegar is acidic, and if too much of it remains in the fabric after washing, it can affect the ability of your mordant to bond correctly, and it may also mess up the color of certain pH-sensitive dyes. In the case of yardage, it’s a good idea to either zig-zag or serge the raw ends, or at the very least, to re-cut them with pinking shears, to help prevent fraying.
But it was advertised as Ready-to-Dye
Ready-to-Dye (RTD) blanks are sold in many different places, and some of them really are ready-to-dye. Some of them aren’t. I have certain vendors whose word I trust, and I will use their products without scouring first, though I always launder first. In the case of RTD items, I run them through the laundry with hot water and using Tide, but no fabric softener or other products.
Re-purposed and upcycled clothing
I love to remake used garments. I love the challenge of “rescuing” things that have been cast off, and I feel good about lowering the environmental demands of clothing manufacturing. I also feel much braver when I am experimenting with a new technique or material when I am using a garment I paid $5 for at the Goodwill, versus a $20+ dye blank.
There are some special considerations when it comes to prepping used garments for dyeing. First of all, you will need to pre-treat any visible stains and launder with detergent in the machine. I use Shout spray on stains. If the stains are not gone after laundering, I may try using oxygen bleach, but when I do this, I run the garment through a third time with only water, to make sure there is no residue left. If there are any visible stains left after that, you’re faced with a choice: incorporate the stains into the design, or give up the idea of dyeing that item. For this reason, I have given up buying anything with visible pit stains. They only come out about half the time, and it’s pretty hard to think of an appealing design element in the armpit! One possible work-around is to cut the pit stain out and replace it with a gusset in a different fabric or pattern.
After laundering and removing the visible stains, you’re going to want to scour any used garments. I mean every last one. This white cotton skirt is a perfect example. When I picked it up, it appeared clean and stain-free already. It smelled laundry-fresh, but I ran it through the laundry anyway because I had no idea whether the previous owner might have used chlorine bleach, vinegar, or fabric softener on it.
The skirt needed a new elastic waistband and it had a small tear, which I plan to repair later with a visible mending technique, but I am leaving both of those repairs until I am done with the prep and dye processes. The scour process finished off the already-weak elastic, and I will be applying more heat as I dye it, so I’ll just fix it when I’m all done. As you can see, the skirt came out of the laundry looking nice and white and, if not for experience, I might have skipped scouring it.
For the first half an hour, the scour water looked clear and I was thinking I might not need to go the entire hour. Somewhere around the 40-minute mark, though, I started to see the water looking brown, and this is how it looked after an hour. Some of what came out may well be residue from the laundry detergent, but some of it is gunk that was embedded in the fabric and too tough for Tide to clean out.
The incident that led me to promise myself never to skip scouring a used garment again was a bit of a heartbreak. I bought a blouse that looked to be in excellent condition, it was well-made and I was completely smitten with it. After laundering, it looked perfectly white, so I didn’t scour it before dyeing. When I pulled it out of the dye, I was crushed. There were these weird, unevenly dyed streaks down the side seams, like where your arms would hang while wearing it. My best guess is that it was residue of some kind of lotion, body butter, or oil the previous owner used on her skin. There was no sign of it at all until I dyed the blouse. After dyeing, whatever it was seemed to be permanent and I was never able to salvage that project. So much time and effort wasted! Lesson learned.
A dirty example
In some cases, you have to deal with fabric that is really dirty. In other cases, like I mentioned at the beginning, you may have to deal with other substances that are hard to remove. One dyer, whom I met in a Facebook group for natural dyeing, shared the most incredible example I’ve ever seen. Whatever the piece was, it must not have been very big, because she was scouring it in a large sauce pan, but it had so much starch in it that when she went to change the water, she found that she had a brown, gelatinous disk at the bottom of her pot. Most of the time, you’re not going to encounter that level of gunk, but it’s fairly common to find that you need to scour something repeatedly to get it ready to dye.
A friend gave me several pieces of heavy cotton fabric that was meant as liners for obis. It’s heavy and so tightly woven, it is almost waterproof, and it was starched heavily for its intended use. When I went to grab it from my work space, I discovered that it was also filthy because the bag it was in had torn. I knew I was in for a long scour process, so I set my mental mode to “extreme patience,” and got to work.
After trying to wash the first piece in the machine earlier on, I learned that that was a waste of time. This stuff needed to soak and simmer. So, I whipped up pot #1 of scour water. It’s important to have enough room in the pot for the fabric to be moved around when you stir. If it’s too packed in too tightly to move, some of the fabric will not get the full benefit of scouring, and you may get uneven results with mordant and dye later on.
As I mentioned earlier, scouring cellulose fibers takes detergent, soda ash, hot water, and time. Often, I’ll use a volumetric “generic” recipe for scouring solution, but in this case, I decided to go strictly “by the book,” weighing the filthy fiber and calculating the amounts of soda ash and Orvus based on percentages of the total weight of fiber (WOF). You may see other dyers (often abroad) who will call this weight of goods (WOG), instead. After weighing, I learned that 2 ounces of soda ash by weight equals a quarter cup. Your mileage may vary.
The first pot turned about the color of chicken stock within 20 minutes. In many cases, you don’t start to get the full scouring effects until 30+ minutes. Depending on the fabric and the level of dirt or starch, you might simmer it for up to two hours at a time. In this case, though, I knew I would be doing multiple scours, so I planned to let the first scour go for an hour.
Scouring uses a lot of water and stove fuel, which is a main reason people choose to skip it. At home, I use a propane stove outdoors because propane burns efficiently and is cheaper than buying the butane cans that my portable stoves use. With the small stoves, I burned a can of butane for each scour pot, which are about 4 gallons each.
By the time the first pot had simmered for 45 minutes, the water looked like beef bullion, and I was not convinced that it was going to do much good to continue simmering in such nasty water, so I pulled the fabric out and let it cool in a colander while I dumped the water and made a fresh pot.
While the second pot heated, I took the fabric to the sink to give it the most thorough rinsing and wringing I could. No point in bringing old muck into your new pot, right? At this point the fabric still felt almost as stiff as when I started, so I knew there was a lot more starch still to come out. I typically wait until the pot is about 100-110F before adding the soda ash, and I wait for the water to become clear again before adding the detergent. Once the scouring solution is well mixed, I add the fabric and bring it up to a simmer.
After 20 minutes, the second scour was still almost clean, which let me know that I’d at least managed to get the worst of the dirt out, but the fabric was still ridiculously stiff. Even though it was thoroughly saturated with water by this point, it was still a little resistant to bending. Time and heat do eventually get the job done, and by the end of the first hour, the fabric was much softer.
By the end of two hours, the water was showing dirt, but nowhere near as dark as the first scour. If dirt were my only concern, I might have rinsed it out at this point and called it good, but I was pretty sure there was still more starch to remove, so I rinsed and wrung and made a new pot of scour solution.
Since it was getting late in the day, I simmered for an hour, then left it to soak overnight. By morning, the water was only about half as dirty as you see at the end of scour #2, and the fabric was much more pliable. It’s never going to be a soft fabric because it’s made with fairly thick threads and very tightly woven. So, I gave it a final rinsing and wringing and hung it to dry. I had expected to photograph it dry by the end of the day, but it was still pretty damp when I left it today. I’ll update later!