Therefore, this post is going to center around the idea of discharging dye, using basic easily-accessible means. I started to write up this long block of text about the intricacies of such thing from a chemical/technical side, but realized that 99% of the people who might ever read this would either not really care, or not need to know the specifics of that. So I will just sum it up very briefly…
There are two ways that dye can be removed from fabric chemically; oxidizing agents and reducing agents. Oxidation occurs by "removing" something chemically from the dye, either causing it to "let go" of the fabric, destroying the pigment, or both. (Chlorine) Bleach and Hydrogen Peroxide are good examples of this. Both cause a bit of wear and tear to the fabric with each use, and can cause unwanted side-effects (certain colors removing at different rates, or discoloring), and bleach is the worst culprit of both; bleach can even totally destroy certain fabrics on contact. Metal becoming rusting is a good example of destructive oxidation, when you scrape away the rust to get to the unaffected surface underneath, there is no way to bring back the "missing" metal; each time you use bleach a small (or large) amount of the fabric surface is "scraped away". However, in certain circumstances it is the best or only option. For discharging dyed fabric though, it is often not a good choice.*
Reducing agents (in the context of discharging) instead "add" something to the mix, once heat is applied, causing the dye to release from the fabric into the water that the agent has been added to, and often helping prevent it from reattaching to the fabric. In some cases a chemical process (generally with additional heat) occurs to destroy the dye in place - leaving un-dyed or greatly lightened fabric in its place - without needing to be immersed in water. These are the products that are best used for removing dye from fabric; perhaps something was dyed improperly and you want to give it another go, perhaps you want to try a new technique in certain spots, perhaps you want to revitalize an old garment…all are good candidates.
Now things get a little confusing here, because there are some dyes that must be "reduced" in order to attach to the fabric (indigo dye for blue jeans, for instance, and certain commercial dyes), and therefore the only optimal way to remove them is through oxidation (i.e. bleach, peroxide), but going into all of those details would require a longer post of its own. Needless to say, what I will focus on are reducing agents, but results may vary depending on the type of fabric and whether it was factory-dyed or not).
The most easily attainable discharging product is Sodium Hydrosulfite, usually paired with Sodium Carbonate (aka washing soda, soda ash). You can find this in many "off the shelf" products for fixing dye accidents or color run removal, such as Rit Color Remover or Carbona Color Run Remover.
Dylon makes products called SOS Color Run Remover and SOS Color Remover (for Whites Only), but I have not used them and can not find any MSDS/ingredient info on them, so I don't know how well they work or when they should be used. I would suspect that the first is a typical hydrosulfite-based product and the second is a bleaching product based on the descriptions but I have no way of knowing.
In addition, Jacquard produces an iDye Color Remover; this is a different chemical (Thiourea Dioxide) which is best suited for removing certain types of dyes, specifically fiber-reactive and direct dyes. Their iDye product falls into this category but many others will not and results will be mixed.
Having used both the Rit and Carbona products, I prefer Carbona; for around the same price you get slightly more product, and I have had better results with discharging using a single packet with hot-from-tap water in a washing machine. To make things slightly confusing, Rit has a slew of products with similar names and similar use, and I am just going to quickly mention them here for clarification.
Rit White Wash - This has the Hydrosulfite/Carbonate pair, but also includes water softeners. Based on the description and ingredients I believe it to be a slightly lower concentration and geared towards removing light dye and water/detergent/etc deposits (i.e when your whites begin to "gray" over time)
Rit Whitener and Brightener - Surfactants/Detergents and Optical Brighteners. This is simply a chemical to make whites appear brighter. No lightening action involved based on the ingredients.
Rit Stain Remover - Surfactants/Detergents. Basically a bottle full of concentrated "Stain Remover Pen" liquid.
Rit Rust Remover - This is also Hydrosulfite/Carbonate, with added surfactants and chemicals to inhibit oxidation (presumably to help remove rust stains specifically). Haven't used it.
Rit Fast Fade - This is Sodium Carbonate and Sodium Dichloroisocyanurate (essentially powdered chlorine bleach). This is how you would want to discharge blue jeans/denim, etc, but it's fairly hard on the fabric in the process and will cause unwanted results on certain dyes/fabrics. If this post doesn't get too long, I'll go into this a little at the end.
Anyway, the main reason for all this is that if you find a product that you are not sure of, but it's primary ingredients are Sodium Carbonate and Sodium Hydrosulfite you should be good to go! Unfortunately while Sodium Carbonate is easily available as "Washing Soda" in most stores, (and is good to have on hand for various reasons if you do a lot of dyeing and dealing with fabric), Hydrosulfite is not…which is just as well, as it is hazardous in large quantities and degrades over time. So, it's best to just obtain the small packages of whatever-brand dye remover as you need it.
But enough ramble, on to actual material and pictures!
So I happened upon this sort of sweater-with-built-in-collar and I thought "This would be perfect for that one costume that has an inexplicably collared sweater-thing in its design, well, if only it was red." Normally I would find some other method or just make it, although I don't particularly like sewing knits, and you don't find much in the way of ribbed sweater style knits just laying around on the bolt, much less in a specific shade of red…but anyway. So I had the stuff on hand and I thought I'd have an experiment, and then blog about it as an example! Now one reason I also thought this particular thing was a good candidate was that it was 100% cotton, and it had a warning about washing in cold water only (practically a guarantee that it wasn't colorfast, even when washed normally).
Unfortunately, I don't have a picture of when I first began, but only after I had initially wet the garment (and realized I should document the process). Also, just like with dyeing, it is good to prewet the fabric beforehand when doing something like this.
This is the Carbona product I mentioned earlier as well.
Placed in a bucket of hot water (luckily I have tap water that gets extremely hot, scalding even. Well, lucky for dyeing. Not so much when you accidentally turn the tap too far in the shower.) it began discharging immediately. At first it was a sort of brownish-reddish color, but it quickly turned to black, so much so that the bucket looked like it was filled with ink.
I don't have a picture of the later stage, but here is when it first began to discharge.
Now if you are doing this in a bucket, it is ideal to have a fan or good ventilation. It has a very distinctive odor, fairly unpleasant, and it's best to not breathe in a ton of it. It's not exactly toxic gas that you need a respirator for, but at the same time it's not particularly good for you either. If you do it in the washing machine, it seems to be better contained, however.
Ok, so after the first treatment and drying I now had a garment that looked like this:
It's nice and all, but I thought I'd try one more go and see if I could get it lighter; when discharging the first time the water reached a point where there was so much "loose" dye in it that I suspected that no more was leaving the fabric. Unfortunately, here is where an accident happened. I thought I would try something different and use the Rit Fast Fade I had on hand, I'd used it before with good results but didn't really consider the fact that it had chlorine bleach in it. As soon as I added it into the wash (and smelled the overwhelming chlorine assault) I reconsidered my decision, but figured I would just go for it at that point. Not only did it not discharge further, but it left the entire thing stained a very ugly beigey-yellow color, with uneven blotches like water marks, once it dried. Fortunately I was able to resolve this, but there's not pictures at this stage because I worried I had ruined it.
(link for bleach post tba)
After fixing that problem, (mind you, each stage I let the fabric dye fully and "rest" a little before starting again the next day, didn't want to stress it too much), I discharged it one last time, this time in the washing machine. You can see how much dye came out again, despite it being a fairly light shade of gray.
After drying one last time, I ended up with this…it's actually a bit lighter than it appears, but it was night time and indoor lighting and all that.
At this point I figured it was good enough to dye; most dyes, especially on store-bought clothing, will not remove completely, or else not without a substantial amount of wear and tear to the fabric. I had already tormented this enough and it seemed lightened enough, so I figured it was time to dye it. One unpredicted side effect was that the snaps on it had begun to rust, possibly due to the chemicals, or being routinely damp over several days, or both. I intended to replace them anyway, but I removed them at this point. You can actually better see how significant of a difference it is, this way, anyway.
Good thing there's more snaps going back over it, right?
Aaaaaand here's the final product, dyed with Rit Cherry Red. I suppose that was a lot of work to save some time, but hey, it was an adventure, and you learn something new each time, you know?
So, yeah. Cottons and natural fibers will probably discharge best using this method, some synthetics will but the majority of it will not. A "wash with like colors" and/or "cold wash only" care tag is a good indication that the dye might not have a iron grip on the fabric and be easier to dislodge, but it may also mean that the fabric is delicate or may be ruined by hot water. Rayon, silk, acetate…many of these require gentle treatment. However, if you have the time and means to experiment, by all means do! There's a lot of interesting things you can do. Next time, I'll do a post on discharging specific parts of a piece of fabric without having to affect the entire piece. That part is pretty cool, and has a lot of neat possible applications.
