Monthly Archives: November 2017

Is hydrogen peroxide effective at stopping the damaging effects of chlorine bleach?

Name: Denise
Country or region: United States
Message: Hello Paula –
Hydrogen Peroxide is said to be ineffective as a bleach stop….I have been perusing your website to solve a problem I have with a Pier 1 seat / back cover for a director’s chair. I wanted to remove the color from the fabric, 100% cotton canvas, but chlorine bleach wouldn’t work! Anyway, I was double-checking about a bleach stop to neutralize the bleach I used and I see you still recommend Hydrogen Peroxide. Do you still? I found another resource that says it’s ineffective. It makes reference to a book by Rayna Gillman. Here’s the link: About Bleach Neutralizers, by Natasha Gilani. Let me know what you think ……Thanks. Denise

Thanks for writing, Denise, and thank you in particular for including your reference. I do still recommend the use of hydrogen peroxide for neutralizing chlorine bleach.

Rayna Gillman is mistaken, I think, and I think that Natasha Gilani could use some more authoritative sources. The only mention of peroxide in Gillman’s book reads:

“Anti-Chlor (sodium bisulfite) is the only substance that stops chlorine bleach from destroying fabric. Neither hydrogen peroxide nor vinegar (two old wive’s tales) will do the job. Anti-Chlor is available from ProChem, and a similar product is available from other dyehouses.” (Page 61 of “Create Your Own Hand-Printed Cloth: Stamp, Screen & Stencil with Everyday Objects”, 2008).

There’s no additional supporting evidence, and no reference for her assertion. I think it’s merely an error in which she conflated the effectiveness of hydrogen peroxide with that of vinegar. A larger error is her claim that sodium bisufite is the only substance that can stop damage from chlorine bleach. Dharma Trading Company’s Bleach Stop is a different chemical, sodium thiosulfate; while it is less economical than sodium bisulfite, since a larger quantity of it must be used, nobody (as far as I know) asserts that it is any less effective. I recommend Anti-Chlor over Bleach-Stop only because of the convenience and economy of being able to use a much smaller volume of the chemical; they are equally effective at preventing damage.

In my own experience, hydrogen peroxide, the ordinary 3% strength commonly sold for use as an antiseptic, is highly effective as a bleach stop. Garments on which I’ve used hydrogen peroxide as a bleach stop have survived years of heavy use by my family; when my son eventually wore one of them out, after years of frequent wear (it was a favorite of his), it was the seams that failed, not in the area of the bleached-out designs. This is in spite of the fact that the navy blue dye of that particular shirt was rather resistant to the bleach, so I had left it to bleach for considerably more time than other items. Another shirt even now continues to be worn occasionally by my husband, fourteen years after I neutralized a bleached-out design on it with hydrogen peroxide, and there is still no sign of degradation of the fabric in the bleached-out areas! (Unfortunately I don’t have any unneutralized bleached shirts for comparison.)

Now, hydrogen peroxide might not work if it has been sitting on the shelf for a long time. Hydrogen peroxide is quite reactive and will eventually go bad. If a bottle is still sealed, it may be good for up to three years after purchase, but once the seal has been broken, expect it to last no more than a year. In fact, its full effectiveness starts to decline within a month or two after the bottle has been opened, so it’s best to use a recently opened bottle for critical uses like neutralizing chlorine bleach. I don’t know how fresh my bottle was, but obviously it was fresh enough. I rinsed the bleached fabric with water, and then poured the peroxide over it.

Hydrogen peroxide is less economical than Anti-Chlor or Bleach-Stop, but it’s not unreasonable in cost. It has a real advantage, moreover; unlike either sodium bisulfite or sodium thiosulfate, it doesn’t present any risk to asthmatics. Five or ten percent of people with asthma are sensitive to sodium bisufite and are better off if they avoid exposure to it (though I imagine that using it as a bleach neutralizer would probably be safe even for people with sulfite-sensitive asthma, if they wear a respirator with an acid gas cartridge).

To compare the effectiveness of hydrogen peroxide with vinegar, for neutralizing the hypochlorite in chlorine bleach, it’s worth taking a look at the chemical reactions involved. The chemical reaction between hypochlorite (the active ingredient in chlorine bleach) and hydrogen peroxide is as follows:

OCl- + H2O2 -> Cl- + H2O + O2

It produces chloride ion, which makes sodium chloride, i.e. ordinary table salt, plus bubbles of gaseous oxygen. In contrast, the acetic acid in vinegar reacts with the hypochlorite to produce sodium acetate plus hypochlorous acid:

NaOCl + HOAc <-> NaOAc + HOCl

In the presence of acid, hypochlorous acid degrades to form chlorine gas. It is quite unlikely that a home dyer will use a large enough quantity of acid to produce lethal accumulations of chlorine gas, but the fact (as I’ve heard it) is that hypochlorous acid is even more damaging to fabric than hypochlorite, so it’s hardly an improvement. Deaths and serious injuries caused by mixing chlorine bleach with acids have all involved a much stronger acid than vinegar (a strong phosphoric acid solution used for cleaning toilets has sometimes been mixed disastrously with chlorine bleach). Chlorine bleach as supplied for home use is supplied as a mixture with extra sodium hydroxide in order to help prevent the reaction of chlorine bleach that occurs with acid.

For more information on neutralizing chlorine bleach, please see my page, “How can I neutralize the damaging effects of chlorine bleach?”.

For your canvas director’s chair seat and back, after you have washed out the chlorine bleach and used either peroxide or Anti-chlor to prevent damage from the bleach….although bleach did not work to remove the color, it is possible, though far from guaranteed, that a reducing type of color remover might work. Bleach and color removers work in a different way, so sometimes one works when the other does not. Howveer, some dyes simply cannot be removed, and it is impossible to know what dyes were used in your covers. See my page, “What chemicals can be used to remove dye?”. Alternatively, you might use the old seat and back as patterns to sew new covers from undyed cotton canvas. If a beige color will do, Pier One currently has new director’s chair covers, in “sand”, on sale on their website.

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I have used alcohol inks to paint on silk and wonder how best to fix the dye

Name: Tina
Country or region: usa
Message: I have used alcohol inks to paint on silk and wonder how best to fix the dye. I used a water based resist and would like to wash it out in water but am afraid the water will wash out the ink before it is set. I could iron but wonder if you recommend a fixative.

I’m afraid I don’t have the answer you’re looking for. Alcohol inks are not suitable for painting silk that will ever be subjected to the rigors of washing. They are intended for coloring materials that will never be laundered; for example, they are good for painting fabric that you are then going to frame and use as decor, or for painting wood, glass, or metal ornaments. There is no fixative that will enable the alcohol inks to function as real dyes. There is a way that you might fix it permanently in place using a colorless fabric paint, but the results may or may not be what you’re looking for. The biggest problem is that anything you can use to fix your alcohol inks will also fix the resist in place!

It is important to use the right material for a project. For painting on silk, I recommend using good silk paints or silk painting dyes. There are many excellent choices available. Take a look at the silk painting section at a good dye supplier. For example, see Dharma Trading Company’s page of “Paints and Dyes for Painting Silk, Wool, and Nylon Fabrics“. Every one of the dyes and paints on that page is far more suitable for silk painting than are the alcohol inks. It would be good to start by reading some books about silk painting, such as Susan Moyer’s Silk Painting for Fashion and Fine Art, or Mandy Southan’s Beginner’s Guide to Silk Painting. There are some differences between silk painting and watercolor painting on paper.

The most intensely beautiful results in silk painting are obtained by using dyes that are then fixed by steaming. (Unfortunately, steaming will not fix alcohol inks on silk.) Among the silk dyes Dharma carries, and which are also carried by other good suppliers, I recommend Sennelier Tinfix Design Silk Dye or Dupont Silk Dyes, if you want your dyes to be ready-to-use in a wide range of different colors; alternatively, I recommend Jacquard’s Vinyl Sulphon Liquid Reactive Dye Concentrate, if you are willing to mix your dye paint for yourself, especially if either lightfastness or economy are particular issues. (See my page, How to Dye Silk.)

Very nearly as beautiful are the results produced with silk paints, which are fixed by ironing. The effects are very similar to those of silk dyes. They contain pigments, rather than dyes; a pigment must be attached to the fabric by a fine glue-like binder, which is included in the paint. Usually the binder is one that is activated by high heart, such as by ironing to heat-set. Alcohol inks are missing this binder component. You can get lovely results by painting with a specially-made silk paint such as Pebeo Setasilk or Jacquard Products’ Dye-Na-Flow fabric paint. PRO Chemical & Dye sells a similar silk paint called PRO Silk & Fabric Paint. Fabric paints always leave at least a slightly perceptible change in the feel of the silk, unlike silk painting dyes, but the convenience of not having to use extensive steaming (in a silk steamer) to set the dye causes a great many artists to prefer it. Silk paints leave a much less noticeable change in the hand of the fabric than do other textile paints. Some water-based resists that you can use with silk paints will be fixed in place by heat-setting, while other will wash out easily even after ironing. Silk paints themselves can be used as a water-based resist for steam-set silk dyes, but they can’t be expected to wash out 100%.

Now you know what you should use next time, but how are you to salvage this current project? The first and most effective option is to preserve it by never washing it, and retain the resist that you used exactly as it is now. There is no guarantee that anything else that you try will work out satisfactorily. If never washing your painted silk is not an option, you can TRY to set the pigments in place using a clear, colorless fabric paint or fabric medium; this will inevitably fix anything else on the fabric in place permanently, as well, though, whether it is a resist or a random fleck of dirt. Dharma Trading Company (and other Jacquard Products suppliers) sells a fabric medium they call “Lumiere and Neopaque Extender” in containers ranging in size from two ounces to one gallon; the same product is listed elsewhere as listed elsewhere as Jacquard Products Neopaque Flowable Extender. This is the exact same material as the fabric paints that have colors, but without the pigments. You can dilute this material by no more than one-quarter with water (e.g., mix one ounce of the clear extender with one-quarter of an ounce of water); using more water interferes with its effectiveness at holding the pigment in place on the fabric.

It is always essential to test your materials and methods before spending much time and material on using them. Since you have already obtained a design that you do not want to spoil, you would need to test whether fixing it with fabric paint extender will work, or whether it will ruin what you have. Create a small quick test painting using the same inks and resist material, one that is similar in application method to your current design, on a piece of scrap silk, and do a test of the following method. Given the wide variety of things that different people will try, nobody can guarantee that a material will work the way you want it to with what you already have; you must always do a test first to see how you like the way the materials work together.

To use the fabric paint extender to try to make your alcohol ink design permanent on silk, you would paint your design, after it is completely dry, with Lumiere and Neopaque Extender on both the front and the back side of the fabric (letting the fabric dry before turning it over to do the second side). Be very careful, as the liquid in the extender might lift some of the pigment, distorting your design. After the extender you have applied has been dry to the touch for 24 hours, you can heat-set it to make it permanent. You can do this by pressing, according to the manufacturer’s instructions, with a hot iron for thirty seconds on each side, or by putting it in a commercial clothes dryer for an hour (home clothes dryers do not get hot enough). If heat-setting is impossible, some artists have reported that allowing the fabric paint to dry and cure at room temperature for a long period of time, more than one month, seems to produce an adequate degree permanence, as well, though this is not among the manufacturer’s recommendations and might not work as well.

There are other brands of fabric paint medium that might be used for this purpose, as well. In her 2008 book “Quilts of a Different Color“, published by the American Quilter’s Society in Kentucky, Irena Bluhm gives a recipe for a mixture of colorless fabric mediums that she uses to seal pigment she has drawn with ordinary colored pencils onto fabric, which she then uses for quilting. Her favorite formula is to mix 70% Jo Sonja’s Textile Medium, 20% Delta Ceramcoat Textile Medium, and 10% Versatex Fixer. The different textile mediums have different textures, and it is a matter of taste, which you prefer. Delta Ceramcoat is very thick, while Jo Sonja’s Textile Medium is thinner. These two textile mediums require heat setting, but the Versatex Fixer allows the use of this mixture with no heat setting at all. The combination of mediums with fixer must be used immediately after the Versatex Fixer has been mixed into it.

Remember that using a fabric paint extender or fabric medium in this way, in order to fix a non-permanent pigment that was never intended for permanent use on fabric to be washed, can only be regarded as experimental. How successful it will be will vary depending on the performance of the specific ink that you used, and also depending on other variables such as how thickly the ink was applied, how sturdy the silk is, or on how frequently you plan to clean it. As far as I know, there is no method that has been tested and shown to nearly always be acceptable for permanently fixing whatever brand of alcohol ink you used on silk. If this particular piece is precious to you, it would be best to save it as it is now, without washing out the resist, and to immediately invest in a proper silk paints or silk painting dyes for your next project on silk.

I’m sorry I don’t have a way that will allow you to wash out the resist without damaging the alcohol ink painting.

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[The paragraph on Irene Bluhm’s fabric medium mixture includes some sentences that previously appeared in my blog entry, “How can I set inkjet ink that I’ve already painted onto cotton?“, March 23, 2012.]

Pre-reduced indigo: natural versus synthetic

Name: Jen

Country or region: US

Message: I’m doing research on pre-reduced indigo crystals. I’m finding that they’re being called everything from freeze-dried to instant and claims of them being ‘natural’, extract, etc. This flies in the face of what I’ve also been told directly by an importer- if it comes from India it’s all synthetic. Even the stuff one seller is claiming produced in Japan has an import label from India! So you can see confusion.
Any information or insight you’d be nice enough to share is most appreciated.

Hi Jen,

I believe that I’ve NEVER encountered pre-reduced indigo that was not synthetic. Those who wish to use only plant-derived indigo must do more work to reduce their indigo themselves.

I suspect that there is no difference at all between pre-reduced indigos that are listed as being freeze-dried, dried, or instant, merely different ways of describing the same product. Indigo “extracts” appear always to be the normal oxidized form which must be reduced by the dyer before use. Note that pre-reduced indigo is not 100% reduced; the various retailers all specify that their pre-reduced indigo is 60% reduced. The remaining 40%, which is in the oxidized form, is unusable unless the dyer chemically reduces it in the indigo dyeing vat. (Both synthetic indigo vats and natural fermentation indigo vats produce chemical reduction.)

Often a retailer’s advertising copy reads as though their pre-reduced indigo is natural, but if they are both reputable and careful you can see that it is not. For example, Dharma Trading Company, which is good about what claims they make, says:

As an alternative, try this Pre-reduced Indigo. Synthetic Indigo (chemically identical to natural Indigo) has been pre-reduced chemically, then dried, so it dissolves in water right off the bat….This all makes it have a lower environmental impact for the dyer than taking the original natural or synthetic Indigo from start to finish with all the chemicals involved.

Jacquard Products starts off saying “This natural vat dye exists in plants all over the world”, but concludes clearly with “Jacquard’s indigo is a synthetic organic and comes pre-reduced 60% for unprecedented ease of use.” (source)

“Organic” is a difficult word for the dyer, because an organic chemical is any chemical that contains carbon; it has nothing to do with organic farming. All dyes, whether natural or synthetic, are organic chemicals, aside from a few mineral colors that are not really of interest. However, many dyers mistake claims that a dye is organic, thinking it means it is a plant-derived dye when in fact it is not. Dye sellers sometimes purposefully exploit this confusion.

Jacquard pre-reduced indigo is available through Amazon, as well as other sources; a supplier on Amazon currently selling Jacquard pre-reduced indigo, “The BT Group”, provides misleading information claiming that what they are selling is naturally occurring. There’s an issue with resellers on Amazon, which can post wrong information about their products; it’s likely that The BT Group doesn’t know anything about what they are selling, and merely selected several phrases from the Jacquard copy without paying attention to how they have changed the meaning by omitting a key word. Similarly, Etsy sellers give blatantly false information about whether the pre-reduced indigo dye they sell is from natural sources, when what they are selling is obviously synthetic, given their suppliers.

Earth Guild makes an error, showing instructions for using natural indigo on a page whose title is “PRE-REDUCED INDIGO INSTRUCTIONS”, but I don’t think that the title of a web page amounts to a claim, given that many people who edit web pages don’t even know how to alter the titles of their pages. (source) In corroboration of this interpretation, they have a page on Lanaset dyes with this same webpage title, so it’s just a mistake.

George Weil helpfully says that pre-reduced indigo is used as “an alternative to Natural Indigo”. (source)

There are blogs that have instructions for using pre-reduced indigo which assert that the dye is natural, but in every case it seems that the blogger was insufficiently knowledgeable. Since they’re not selling the dye, they’re not legally liable for their claims in the same way that someone who is selling a pre-reduced indigo is.

If you find any additional information, I will be interested in learning about it!

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