Category Archives: discharge and bleach

Is it possible to bleach this black jacket and dye it yellow?

Name: Sierra
Country or region: USA
Message: Hello!

I’ve been scouring your blog and I don’t see my particular situation being represented. I hope I’m not asking a repetitive question. (I apologize if it is and I just don’t know enough about dyeing to know better)

Hot Topic Black Sweetheart Double-Breasted Tiered Ruffle JacketI’m making a cosplay for this character, Yellow Diamond [shown to the left]. My plan is to buy this jacket, which is 72% polyester; 23% rayon & 5% spandex [shown to the right].

Is it possible to bleach it and then dye it yellow and if so, which method of doing so would you suggest for the best result? Regular bleach or a color remover?

Thank you so much for your time!

No, sorry, you can’t bleach that! Chlorine-based bleach will damage the polyester (turning it an ugly yellow that can’t be removed) and break up the spandex. Non-chlorine color removers require heat which will damage the spandex. Besides that, there is never any guarantee that a commercially-dyed black even can be removed by either means. Many black dyes cannot be removed. When bleached, or treated with other color removers, they may stay black, or they may turn an ugly brown, not suitable for dyeing yellow. It’s rare for a commercially-dyed black garment to bleach out to nearly white.

Maybe you could build something suitable starting from pieces such as, say, a dyeable rayon jacket and a skirt that you cut up the front (and fold over the edges and sew so that it doesn’t ravel), from Dharma Trading Company, which is an excellent source for dyes and dyeables. Look at the skirts on the Dharma site and the jackets there, for example, their waterfall jacket. Since they are white, and made of dyeable materials, these clothing items will dye a beautiful yellow. Don’t forget to check out the accessories section to see if they have dyeable gloves, etc. They also have dyeable cotton/spandex leggings.

If you buy a yellow Procion fiber-reactive dye and dye several white dyeable clothing black garments at once in the washing machine, it will all match beautifully, which is a great aid in designing a costume.

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Can you share the best method for removing color from an old wool rug?

Name: Kate

Country or region: Pennsylvania

Message: Hello,
Can you share the best method for removing color from an old wool rug? Thiox seems to only remove the color on a few random spots, not all over.

I’m afraid that there is no product that will work better than the one you’ve tried.

There are two problems with trying to remove the color from an old wool rug. One is that not all dyes can be removed at all. The other is that you can only remove the dye that you can reach. If the dye is covered with invisible dirt, spilled oil, spilled wax, stain-resistant spray, or just about anything else, the dye will be protected from any chemical you try to treat it with. You have to get the rug very, very clean in order to access the dye, but some stains are impractical or impossible to remove.

Even if you get all dirt and other coatings off of the rug, though, there’s no great likelihood of removing all of the dye. Whether you can remove any of the dye depends on what specific dye it is. You can never tell what dye was used on a commercial product, though; even if you know with one item, an identical item from the exact same suppliers may be dyed with a non-removable dye the next time. Some dyes can be removed easily with a reductive discharge chemical such as thiox; some can be removed by an oxidative discharge such as bleach; some can be removed with either; but some dyes cannot be removed with any chemical you try, no matter what you do. In some cases, you can destroy your fabric, leaving it in rags, and still have color in it.

Wool is easily damaged by high pH. Like your hair, wool requires mildly acid conditions, to protect it. A high pH may lead to obvious damage or to felting. Most color removers are used at a high pH (alkaline or basic), instead of an acid pH. Thiox, which is a brand name for thiourea dioxide, is an excellent color remover, but you do have to be careful not to damage wool when using it, due to the high pH of recipes that call for thiox. PRO Chemical & Dye provides instructions for using thiox to remove dye from cotton, silk, or wool, which also call for soda ash, resulting in a high pH; see their page, “Thiox: Thiourea Dioxide”. Note that recipes for thiox require quite a bit of heat, heating the discharge bath to at least 175 degrees F (79 degrees C); if you used thiox in cooler water, you might find that you have better results with the right temperature. Be sure to neutralize the soda ash in the wool by rinsing with a mixture of vinegar in water afterwards.

Other reductive-type color removers, such as the sodium hydrosulfite in Rit Color Remover, or sodium hydroxymethanesulfinate, which is sold under the name Formosul, will not produce significantly different results than thiox. Formosul is generally considered the best choice for removing color from wool, because it can be used at a nice gentle acid pH, but it will not do a better job than the thiox you tried already, assuming that you used a good recipe for the thiox, and enough heat. PRO Chemical & Dye’s recipe for using Formosul shows the use of citric acid instead of the soda ash used with other discharge chemicals.

As you probably already know, oxidative bleaches, such as the hypochlorite in chlorine bleach, will damage wool much worse than the reductive discharges such as thiox or formosul. I strongly recommend against even trying it. Chlorine bleach is good only for natural cellulose fibers, such as cotton, linen, or hemp.

For more info on dye removal, please see my page, “What chemicals can be used to remove dye?”.

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Do you know where I could purchase a liquid version of sulphur dioxide?

Name: Lisa
Country or region: USA
Message: Hello,

Do you know where I could purchase a liquid version of sulphur dioxide? I’m looking for a color remover that is safe on skin and hair, and also will not change the color of skin or hair. According to your list it seems like sulphur dioxide is what I’m looking for. I read that it’s used as a preservative. Please feel free to provide any other suggestions if you know of anything better than sulphur dioxide. Thanks

Sulfur dioxide, which exists in the form of a gas, is not a particularly safe chemical. It is not safer than the color removers listed on my page, “What chemicals can be used to remove dye?“. In fact, most of the chemicals listed there react to produce sulfur dioxide. They are much safer than the medieval process of burning sulfur to fumigate fabric with sulfur dioxide fumes; their greater safety is due to their making it possible to lessen the total exposure to sulfur dioxide. The biggest problem with any chemical that produces sulfur dioxide comes from breathing its fumes, which can cause asthma, and can, if the amounts are large enough, damage the lungs even of people who previously had never shown any tendency toward asthma.

The way sulfur dioxide and other sulfur-based color removers work is by chemically reducing the double bonds that give dyes and pigments their colors. After a double bond in the dye molecule has been reduced to a single bond, the dye molecule no longer provides color, although it is still present. Some colored substances are very susceptible to reducing agents, while others are resistant and do not show a change when treated with reducing agents. Some change from one color to a surprisingly different color. When removing color from fabric, whether you are using a reducing agent or an oxidative bleach, often you will see “off” colors appear. For example, when removing a dark color, you may end up with tan or orange instead of an absence of color.

When dye is applied to hair, the naturally occurring pigment in the hair is frequently intentionally bleached out as part of the process, both to make the added color stand out more, and to make the hair strand itself more amenable to absorbing the dye. As a result, it’s not unlikely that removing hair dye will result in an unexpected color even if the color removing product works perfectly. In addition, not all dye colors are affected equally by any given color removing chemical.

There is a commercial product, called Color Oops Hair Color Remover, which is based on the same hydrosulfite that is the active ingredient in Rit Color Remover. Rit Color Remover is an excellent product for removing dye from fabric or yarn, in fact higher in quality than Rit Dyes. I expect that the formulation of Color Oops is much kinder to the skin and hair. Although I have never used this product and cannot evaluate how effective it is, it seems to me that this category of product would be a better choice when there may be skin or hair exposure than the textile-oriented color removers, since it is marketed for the express purpose of applying to the hair. One caveat: sodium hydrosulfite tends to break down when dissolved in water, so you should expect any liquid hydrosulfite product to have a short shelf life; be sure to buy it fresh each time you need it, rather than using an old bottle you’ve had for a while. Dry powdered hydrosulfite will last much longer.

There is some useful information in the customer reviews of Color Oops at

Other products promoted for the same purpose include VANISH Color Corrector, L’Oreal ColorZap Haircolor Remover, and One ‘n Only Colorfix, among others. It is harder to find out their active ingredients than it was for Color Oops, so I can only assume that they are similar in composition and safety.

VANISH Color Corrector is claimed to “gently reduces the size of the artificial color molecules, allowing the color to be washed away, with no damage to the hair”. While oxidative discharge agents, such as chlorine bleach, which is based on sodium hypochlorite, make color molecules smaller by attacking them and breaking them up, this seems an unlikely mode of action for a product that is claimed to be safe for the skin and hair. Anything that breaks apart dye molecules will probably break apart the proteins in skin and hair, as well. The product probably contains a reducing agent similar to that in Color Oops, which does not change the size of the color molecules, but instead removes their double bonds.

L’Oreal ColorZap Haircolor Remover is described as follows: “ColorZap will not restore hair to its original, natural color. It removes the tint revealing the underlying base from which the natural color has been removed in the haircoloring process.” Although it is supposed to leave the underlying natural color unaffected, if any of it still remains, a customer review claims that it does lighten the original color of the hair, more than Color Oops.

(Incidentally, you see both spellings, “sulfur” and “sulphur”, in print. Which is correct? It depends on what publication you are writing for. “Sulphur” is the British spelling, while “sulfur” is used in American English and is the spelling recommended by IUPAC, the International Union of Pure and Applied Chemistry.)

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