community of dyers

1. I read that I should fix the color with soda ash after going through the dyeing process to avoid sharp line. How exactly should I do this? Right after the fabric is done soaking in the dye and while it is still wet? Won't that result in mixing around of colors? Or should I wait until it is dry (like overnight?)

6. I also read in a thread that an after-fixer (hopefully I'm using the correct term) can be useful to smoothen out the lines. At what stage and how would I apply that to the fabric?

The after-fixer would be either the soda ash, or a substitute for the soda ash. I don't think you want to use AfterFix, which is sodium silicate, because it would take a lot to do all that fabric, it would cost a lot more than soda ash, and you mustn't allow it to dry, which would make it more of a pain.

If you after-fix with soda ash, there is the problem of possibly dissolving the dye off of the fabric when you apply the soda ash, especially if you are dipping the whole piece instead of, say, spraying it on. A work-around for this is to use a saturated salt solution to mix your soda ash in. If you dissolve as much salt as can possibly dissolve, so much so that a little bit is left undissolved even after extensive stirring, then the dye will be far less soluble in the soda ash solution. The solubility of salt (sodium chloride) in water at 25°C (77°F) is about 360 grams per liter. 360 grams of salt measures out as 166 ml, a little under 3/4 cup. For a gallon of water, that means you should add at least three cups of salt. (Use twice as much if you're using kosher salt, since the large crystals mean you have less salt per cup.) Using a little too much salt is fine, as the excess will just sit at the bottom of the container. Using too little would be bad because it would have less effect on the solubility of the dye.

2. What kind of container should I use for fixing with Soda Ash? You can see that my set-up is a large plastic tub for the dye-bath with the fabric folded accordion style and suspended in it with hangers.. Do I just empty the dye solution and fill it with water and dissolved soda ash and suspend the fabric in it the same way it is hung for dyeing? Or can I unhook the fabric from the hangers and then suspend it in a separate, smaller container with the soda ash and water? Approximately, how long does the fabric need to stay in soda ash?

The fabric needs to be in the soda ash just long enough to be penetrated with it. Then you must keep the fabric moist and warm long enough for the dye to react, either in the soda ash solution or separate from it.

3. Does the quantity of soda ash to be used depend on the weight of the fabric or the quantity of water or both, in this case? For example, how much soda ash and water should I use for say 2 lbs of fabric?

The quantity of soda ash needs to be sufficient to raise the pH of the fabric, where it is contacting the dye, to 10.5. Fortunately, you can get close enough even if you use too much or too little soda ash. If the pH is too high, over 12, you may see more blotchiness and a less smooth color, so that's something to avoid. If you add the soda ash directly to the dyebath, follow the Dharma or ProChem recipe for immersion dyeing, but if you're adding the soda ash separately, you might do better to use the same strength of soda ash that ProChem recommends for the soda ash presoak stage of tie-dyeing. Can you tell that this is all still experimental, trying to get a smooth gradation on a hand-dyeing scale, without industrial machines or processes?

4. About water temperature: For the actual dye bath as well as soda ash fixing. Even when I started with warm-hot water, the dye-bath cooled down significantly during the process. Would that be a problem? Also, what should the ideal temperature of the solution be during fixing with soda ash?

You don't want the temperature to fall below 70°F (21°C). I there some way you can add more warmth? Say, temporarily heat that room in the house with a space heater, or set the bucket inside a bathtub of hot water....

5. Would Urea have any role in avoiding the transition/gradation lines?

No, I don't think so. Urea helps wet fabric stay moist long enough for a slow reaction, and sometimes it helps you dissolve a little more dye in a given volume of water. I don't think it does much else.

What MIGHT help would be a surfactant, such as Calsolene oil, or alternatively Synthrapol or Photoflo, something to help smooth out the wettingof the fiber. I imagine that Calsolene Oil might be best because if it's not any better than Synthapol, why would Dharma even sell it? But there are lots of possible reasons, so I must admit that that's no proof of anything. I really think that you should use a surfactant to try to help smooth out the lines.

I wonder if it would help any to wet-out all of the fabric overnight (or longer) with a bit of surfactant, before you ever start the dyeing process.

Sorry this reply has taken me so long, it's a complex one, and of course I always hope someone else will jump in and answer! I have done only a little gradation dyeing, so all I can share is ideas and information from multiple sources, not direct experience. I will be very interested to see how this works out for you.

-Paula

thank you for posting, I found this very interesting. My question is the fabric being used. If you were using silk, would you still use soda ash? Would the process be the same or is this for bast fibers only?

Lorri

http://www.lasfibers.com
http://www.lasfibers.blogspot.com

I have dyed silk with soda ash and with vinegar, when using Procion MX dyes. There are good reasons for either choice.

I prefer soda ash because it does not require heat-setting. If you dye silk with acid instead of vinegar, the Procion MX dyes act as acid dyes, rather than fiber reactive dyes, which means that it is best to heat your dyebath to something like 180°F, either that or steam the silk afterward to set the dye. I know that there are cool water recipes for acid dyes on silk, but the results are not always as deep in color as desired. Heat is needed for optimum color intensity when dyeing with acid dyes.

Pia prefers to use acid when dyeing silk with Procion MX dyes, because she does not mind steaming, and the premixed dye colors of Procion MX dyes are much more predictable in what color they produce if you use acid instead of soda ash. There is much more shift in color on silk as compared to cotton when you use soda ash. Note that this is only a consideration for premixed colors; for pure single-hue unmixed dye colors, you get very nearly the same color regardless of what fiber you are dyeing.

I don't know whether you'd be likely to get smoother gradations when using Procion dyes as acid dyes instead of as fiber reactive dyes. In general you will get smoother results with a dye that does not bond as quickly to the fiber, I think.

-Paula

Thanks so much for your reply, Paula! I appreciate it very, very much. I do realize it is going to take a lot of trial and error for this to work... But it is good to know the mechanisms and reasons behind some of the techniques. I have a few yards of "practice" fabric here, and will proceed in 2.5m lengths to try the changes you suggested. I do have Calsolene oil on hand. I'll also try to keep the dyeing space warmer (if I do this in a closed bathroom, it'll definitely be over 70 degrees there.) And I'll definitely do the after-soak/fixing in Soda ash saturated with salt. I'll post back with pictures and likely more questions once I've re-tried this in a couple of days... I would try tonight, but I need to get a LOT more salt from the grocery store :-)

I will look forward to other comments and suggestions too. Thanks again :-)

I finally got around to trying some more gradations - some on practice fabric and last night on an actual wrap (thought shorter.) I think I'm getting the smoothness I was trying for :-) Thanks so much for your helpful comments, Paula! I do have a couple more questions (below, after the "details" part) mostly because I didn't get as intense a color as I was hoping for, even at the darkest end.

First, pictures:
Blue, 100% cotton, Osnaburg fabric, 2.7m long, 1m wide:

Brown to terracotta (this was previously dyed terracotta,) Didymos wrap 70% cotton, 30% silk, 2.6m long, 65 cms wide:

Details of what (I think) worked:
I followed the method where I started with the highest concentration of dye (and least amount of water) at the bottom of the tub, and then gradually added water to it to raise the level and dilute the concentration of the dye solution. I think the key to avoiding harsh lines is to add the water in very small increments... I pretty much sat in the bathroom by the vat (with my laptop!) for a couple of hours, adding a couple of quarts of water every two minutes or so at first. Later, I did increase the time interval and amount of water. I was thinking if keeping a trickle of water going in the vat would work the same and if I could avoid the continuous attention needed that way. Unfortunately, the faucet in the bathtub is such that it allows hot water only at the fullest stream, so I can't arrange a slow trickle with it.

Problem and questions:
The problem I'm facing right now is that I'm not getting the depth/vividness of the color desired, even at the darkest/bottom level. I'm wondering if it is because of less-than-required dye, salt, or because I'm not fixing it well enough at the end. In both cases, I used 2 oz. of Dharma procion dye (Teal Blue for first, Chocolate brown for second.) Both fabrics weighed 1 lb approximately. I thought this would be enough dye for them, but maybe I need more because the dye bath is a 30 gallon container? For salt, I'm using a little less than 1 cup per gallon of water (adding some initially and then adding more incrementally with the water.) For fixing with soda ash, I'm using approximately 1 oz per gallon of water. In one case (with the blue one) I let the fabric hang overnight after dyeing, and then put it in a separate smaller tub of water with soda ash and salt dissolved in it. Thus, the fabric was almost dry by the time it went in the soda ash. Do you think that might prevent the fixing process from working properly and could be the reason why I'm not getting as intense a color as desired? In the other case, I let the fabric hang for a couple of hours before I put it in the soda ash. With the blue gradation, I allowed the fabric to soak in soda ash solution for about an hour, and with the brown one, for about 30 minutes. Is that time enough? The solution was made with hot tap water, and kept in the bathroom with the ambient temperature of about 72 degrees.

I had one final question (for now!) I have heard that it is not good for silk to be in contact with soda ash for a significant period of time... Could you say why that might be? Does it affect the luster of the silk, or its structural integrity, or is it simply not true? I'm asking because the wrap I dyed (and am planning to dye at least one more) has 30% silk, and I wouldn't want to compromise it, especially in case soda ash would affect its structural integrity. Is there a time limit (or pH limit) to it within which it would be safe?

Thank you again. I deeply appreciate the knowledge and willingness to share that I've found here.

Wow, those are really beautiful, such perfectly smooth gradations! It's interesting that you are adding more water to let the dye concentration get weaker and weaker, whereas I was thinking of doing the reverse, gradually adding more dye while gradually lifting the fabric out of the dye. It's obviously working well for you.

The problem I'm facing right now is that I'm not getting the depth/vividness of the color desired, even at the darkest/bottom level. I'm wondering if it is because of less-than-required dye, salt, or because I'm not fixing it well enough at the end. In both cases, I used 2 oz. of Dharma procion dye (Teal Blue for first, Chocolate brown for second.) Both fabrics weighed 1 lb approximately. I thought this would be enough dye for them, but maybe I need more because the dye bath is a 30 gallon container? For salt, I'm using a little less than 1 cup per gallon of water (adding some initially and then adding more incrementally with the water.) For fixing with soda ash, I'm using approximately 1 oz per gallon of water.

The Dharma recipe (a good standard to work from) for a 20-gallon washing machine with 8 pounds of fiber calls for half a cup of dye, 20 cups of salt, and 2.5 cups of soda ash. What does this mean for thirty gallons but only one pound of fiber? The dye is going to have more trouble finding the fiber in a large volume. Salt helps with that, but if you're using almost one cup of salt per gallon, that ought to suffice. The one ounce of soda ash per gallon that you're using in your fixing solution certainly ought to be adequate. What's the pH of your fixing solution before you dip your fabric into it?

In one case (with the blue one) I let the fabric hang overnight after dyeing, and then put it in a separate smaller tub of water with soda ash and salt dissolved in it. Thus, the fabric was almost dry by the time it went in the soda ash. Do you think that might prevent the fixing process from working properly and could be the reason why I'm not getting as intense a color as desired? In the other case, I let the fabric hang for a couple of hours before I put it in the soda ash. With the blue gradation, I allowed the fabric to soak in soda ash solution for about an hour, and with the brown one, for about 30 minutes. Is that time enough? The solution was made with hot tap water, and kept in the bathroom with the ambient temperature of about 72 degrees.

Letting the dye dry in the fabric, still unreacted, should not interfere with the dye-fiber reaction once it gets soda ash. Is much of the dye coming off of the fabric into your soda ash bath? A small point concerns whether the Procion dye is getting exposed to too much heat before you get it to the soda ash, encouraging it to react with the water even in the absence of soda ash. Since you're not reacting the dye on the fabric until you dip it in the after-fix, there's no need for much warmth during the dye application step.

I don't know, Anchita, it sounds like you're doing everything right. You could try using more dye to get a darker color, but then the lighter end of the gradation will be darker, as well.

-Paula

I had one final question (for now!) I have heard that it is not good for silk to be in contact with soda ash for a significant period of time... Could you say why that might be? Does it affect the luster of the silk, or its structural integrity, or is it simply not true? I'm asking because the wrap I dyed (and am planning to dye at least one more) has 30% silk, and I wouldn't want to compromise it, especially in case soda ash would affect its structural integrity. Is there a time limit (or pH limit) to it within which it would be safe?

That's difficult to answer for sure. It does seem like a good idea to use soda ash only as much as needed, and not to leave silk soaking in soda ash overnight, say.

It is certainly true that soda ash changes the hand of the silk. It makes it a little softer and less shiny than it would be if you used only acid (plus heat-setting). My silk charmeuse pillowcases are still lustrous after being dyed with soda ash and making many trips through the washing machine as part of the regular laundry, using regular detergent that probably contains soda ash, but not as much so as if they'd never been in soda ash to begin with. They've never shown any wear or gotten any holes in them. I dyed them with LWI with more soda ash than was probably needed, as is my usual habit.

Does exposure to soda ash wear out silk? People do say that, but how true is it? It's apparently not true for the heavier-weight silk that was used in my silk satin pillowcases (purchased from Dharma). I've gotten a bunch of holes (less than one per scarf) when machine-washing much lighter-weight silk scarves, but that was in the absence of soda ash (I was even using Synthrapol, so there was no soda ash in the detergent); evidently the holes were due to mechanical wear (or possibly defects).

Degumming silk is the process of removing the natural gummy sericin protein from silk by simmering it with soda ash and detergent. Pretty harsh treatment, that! Here's a link to a recipe for degumming silk from WormSpit.com. All silk undergoes this treatment at some point before dyeing; in your case, it's done long before you see it.

It is good for silk to give it a final rinse in a very weak vinegar solution, after washing it, to restore a mildly acid pH. If nothing else, it makes the silk feel nicer.

-Paula

I'm pretty sure I had replied earlier, Paula, but it seems to have got lost in cyberspace... Again, thanks a whole lot for your detailed replies!

I've done a couple more projects since, and I seem to be having more success in attaining darker colors by using less water, i.e. filling up only half or so of my 30 gallon tub. I couldn't test the pH of my soda ash solution 'coz I don't have pH paper on hand.. I will include that in my next Dharma order. It is good to know about your experience with silk and soda ash, and thanks for the great tip to add vinegar to the final rinse. It definitely made the silk blend feel softer.

For smooth gradation, I did realize that I either need to add water at short intervals in short quantities, or I could "correct" some of the lines with a paintbrush and some diluted dye solution. It creates more work, but the result was worth it, IMO. Also, I was toying with the idea to let the dye vat fill up very slowly directly with water from the faucet. In theory, it seems like that would make for smooth gradations too. But unfortunately, the bathtub faucet is such that it will allow hot water only at the highest volume setting. I may need to arrange some sort of a hose set-up from the sink to the tub for trying this method out.

Meanwhile, a few pictures from two more wraps I gradation-dyed. The first was already dyed a dusty medium pink color, and the second one was undyed but was a very faint baby blue in its original form and is woven in a "waves" pattern. Both are 30% silk, 70% cotton. I'm also including a picture of the second babywearing wrap in action :-)

It looks like you're achieving the results you want, these are very nice.

Lorri

http://www.lasfibers.com
http://www.lasfibers.blogspot.com