Cochineal dye experiments

May 30, 2015

Another dyer and I got together for a day of dye experiments with cochineal.  We had several questions to which we wanted answers.  The first one and the one which we never resolved was an issue with cochineal washing out of silk scarves.  She used a recipe published in Liles book which uses tin and oxalic acid with cochineal.  We tried washing the dyed scarf in orvis paste and hot water.  The dye washed out.  We soaked another dyed scarf in vinegar and the dye washed out in hot water.  My conclusion is that the hot water is breaking the relatively weak bond between the tin, oxalic acid, cochineal, and silk.  We also tried dyeing silks scarves with the one pot recipe from Garcia.  That also washed out.  Subsequently, I consulted with some other natural dyers and it was explained to me that Garcia’s recipe is more along the lines of an acid dye than a traditional mordant dye so that is why it is washing out.  I assume the tin/oxalic acid is similar.  It was suggested that traditional mordant alum based mordant method would work better.  (As an aside, I looked for the recommended % of alum on silk and it ranges from 5 – 100.  Most of the dye books say mordant like other protein fibers.  I haven’t been able to find any studies that compare % of alum on silk.) Second question: cochineal is very sensitive to water and ph.  It is often recommended that you use distilled water.  Garcia suggests adding cream of tartar to tap water when dyeing with cochineal as the cream of tartar acts as a buffer to what is in the water.  We ran an experiment using different water sources and distilled water with and without cream of tartar.  Below is a picture of the sample cards and a picture of one of the sets of jars with and without cream of tartar.  The interesting observation is that all of jars without cream of tartar had the same amount of particulates in the bottom of the jar.  The jars with cream of tartar didn’t have anything in the bottom of the jar.  My conclusion is that cream of tartar does act as a buffer and it is not worth using distilled water unless you have water that will not work with cochineal.  The three instances that I know of where cochineal would not dye with local water was water that was runoff from a mining area. water with iron, and water in which there was sulfur.  The yarn samples are premordanted with 25% alum.  There are some white, grey, brown, and black wools in the samples. The wool cloth sample is unmordanted.       Finally, I wanted to see the results of two other mordants with cochineal; symplocos (premordanted 50% WOF) and titanium (5% WOF) Below are those results on silk and wool.    


Cotton scarves painted with ferrous acetate

May 15, 2015

This is an old project which I finally finished.  Warps were made with scoured organic cotton, mordanted via the methods in Turkey Red Journal, painted with ferrous acetate of various percentages, neutralized in chalk, rinsed, then dyed in madder and lac.  The warps languished until this spring.  The warp was beamed back to front and threaded using the dogwood draft in Strickler’s book.  The weft is also organic cotton dyed in lac.  The warp was very sticky and a lot of threads were broken in the first scarf.  The second scarf was better as I made sure to check behind the heddles every time the warp was brought forward and split out the threads where necessary.  Kind of a pain but the only thing to do short of rebeaming and having the heddles untangle the threads or cutting off the warp.  I like the end result although I need to figure out a different method for cotton warps if I do this again.  

Cochineal, modifiers, and different types of wool

May 13, 2015

Cream of tartar is often used in dye recipes; particularly in the mordant process.  Various sources say that cream of tartar increases the amount of potassium alum sulphate that is absorbed in the mordant process, improves the hand of wool, and/or brightens red and yellow natural dyes.  In cochineal dyeing, it is important to use if the water contains minerals that make it hard; cream of tartar acts as a buffer and allows the cochineal to bond with the fiber instead of the minerals in the water.  As it is an acid, it will brighten reds and yellows.  It is not clear to me if if the hand of the wool is improved or if it helps with the mordant process.  It seems likely that if you are using hard water, it will act as a buffer and allow more of the potassium alum sulphate to bond with the fiber instead of minerals on the water; similar to the purpose with cochineal.

I usually use rain water when dyeing but decided to experiment a bit with different wools and a different mordant recipe.  For this batch, 20% potassium alum sulphate and 6% cream of tartar was used for the mordant.  The cream of tartar % was not enough to shift the cochineal to red so 10% tartaric acid was added in the dye bath.  The wools were a cormo, a Peruvian wool, and a cashmere wool blend.  The hand was nice on all of the yarns.  The cashmere wool blend (on top) is more orange red than the others but they all seem to have a similar value as far as the color.  No idea why the cashmere blend is a different color.

Acid can be bad for wool (causes it to felt more easily) so I neutralized part of one of the skeins in chalk to see the effect.  I have been told that citric acid, in particular, is bad for wool but am stilling wondering about that as citric acid is routinely used in the chemical dye world with acid dyes.   I don’t care for the effect of the chalk with cochineal (the chalk section is on the left of the skein at the bottom) so will continue to wash the skeins in a neutral soap rather than actually neutralizing the acid.


Down the rabbit hole.

May 12, 2015

Sometimes, a book or an article sends me down a natural dye rabbit hole that consumes a lot of time with not much to show for the effort.  But the exploration is interesting.  In this case, I was reading a book called Natural Colorants  for Dyeing and Lake Pigments Practical Recipes and Their Historic Sources.  In it, there are experiments based on historic recipes which include the use of Potash (K2CO3) either in the dye bath or post dyeing.  I had come across this idea before in Boehmer’s book Koekboya, but never really understood the purpose.  The Navajos and Hopis smoke their dyed wool over wood ash which would seem to accomplish the same end (whatever that end is).  I think I finally found an explanation in Application of Dyestuffs by J. Merritt Matthews.  On page 41, there is a discussion of using a concentrated solution of caustic soda on wool at a cold temperature.  It gives the wool more luster and makes it less susceptible to felting so was used on rugs.  The wool cannot be left in the solution for a long time and it will damage the wool so maybe not a good practice for dyeing. This research led me back to the structure of wool and the question of why different breeds of sheep take dye differently.  Dyers can tell you that a long wool sheep such as churro will take dyes easier than a breed like merino or cormo.  I have never understood why.  I came across a statement in The Science and Teaching with Natural Dyes that dye binds only to the amorphous regions of the fiber and not the tightly packed crystalline regions.  So, perhaps this is the reason the different breeds take dye differently.  I have not come across anything that shows the % by breed of the regions.  There is also a question in the natural dye world, if varying the mordant process will increase the amount of dye take up (increasing the amount of alum).  So, another rabbit hole to explore at some point.   I did come across another statement in Textile Science an explanation of fibre properties that confirmed something that had been in the back of my mind; that for a given weight of wool fibre, courser wools will have fewer fibers than finer wools so one would need to use more dye for the finer wool to get the same color.  That would imply that more mordant would also be required.  Some experiments are probably in order. So, no pictures in this post.  Just a documentation of some of my findings for posterity.

Experiments with cotton shibori scarves

April 6, 2015

Clothroads has cotton shibori dye blanks produced at a mill by Catharine Ellis. I mordanted several of these last year with the recipes that are published in Turkey Red Journal.

I wanted to try the ferrous acetate recipes of Garcia. So, I mixed up some ferrous sulfate and vinegar solutions of various strengths and painted some of the scarves. I didn’t use a thicknener. Two of the scarves were dyed in cochineal. Two of the scarves in a mix of madder and cochineal. They are drying. Then the shibori threads will be pulled and the scarves overdyed.





Natural dye samplers

October 17, 2014

These  pieces have been off the loom for a while but I  haven’t had time to weave in the ends, press, and hem them.  Finally had a chance to get that done,  the wedge weave piece is interesting as each row has a selection of yarns from the same dye pot: silk, wool, superwashh wool, all of which take the dye differently.  The black is not naturally dyed, the other yarns are all dyed with natural dye extracts.

Wedge weave sample

Wedge weave sample

Natural dye sampler

Natural dye sampler



Natural Dyeing in Guatemala with women from Mayan Hands

April 14, 2014

Last spring, at the invitation of Deborah Chandler, Catharine Ellis and Donna Brown worked with some Mayan women associated with Mayan Hands.  The objective was to natural dye cotton with dye extracts.  An article by Deborah Chandler with much more detail will be available in an upcoming Handwoven magazine.  Yarns dyed in the fall after the workshop had some issues so Donna Brown, Rocio (a natural dyer from Mexico and another translator), and I returned to Rabinal in March, 2014.  We got the opportunity to look at the yarns dyed last year at the warehouse in Guatemala City.  They looked like this. 


The skein on the far right is a cotton skein dyed with the same cochineal bugs in the US so something was wrong.  We had them pull the items that were used in the mordant process and discovered that baking soda (sodium bicarbonate) had been used instead of washing soda (sodium carbonate) in the scouring process.  Chalk (calcium carbonate) had been used in the mordanting process.   We had them go through the whole dye process with the correct ingredients.  The end result was this:


The yarns will be available as woven towel kits from Cotton Clouds this fall.

The basic process is an alum, washing soda scour.  Rinse, Tannin soak (they were using tannic acid).  For this they really needed to be careful to keep the yarns covered with water.  If they didn’t the tannin oxidized, turned dark, and wouldn’t rinse out.  Rinse.  Mordant with alum and washing soda.  Rinse.  They are using unmercerized cotton.  We put a couple of mercerized cotton skeins in the pot and they mordanted unevenly.  It is not clear why – maybe they needed to be separated from the unmercerized cotton. 

Once mordanted, the pots were set up as for normal immersion dyeing.  They did have some very nice fuel efficient stoves that really helped this process.




We also started an organic indigo vat with bananas, lime, and indigo.  The bananas were heated and once they sunk to the bottom, the juice was strained off and added to the indigo and lime.  It was left to sit overnight with several stirrings before we left for the evening and some additional stirrings in the morning.  The vat looked like this.


And the resultant yarns:


The tannin bath was reused to neutralize the indigo as vinegar is expensive.

We did some overdyes in myrobalan and osage orange.  The indigo was done first, then mordanted, then overdyed. 

The tannic acid was the most expensive ingredient and we had been told that banana sap contained tannin.  The women had used banana trunk to try and extract the sap but the result did not have enough tannin.  When the opportunity presented itself, a banana tree was cut down and we looked at and tested the sap for tannin.  It turns out it is a good source but has to be collected as soon as the banana trunk is cut.  It is not clear how one would work that out to have a consistent source for the tannin.  There are additional tannin sources that are possibilities and will be explored on a subsequent trip. 

Picture of banana trunk with sap already turning due to oxidizing.



Organic indigo vats

August 15, 2013

In anticipation of the class I am teaching at Taos Wool Festival this year, I decided to get start some organic indigo vats.  I used Garcia’s 1-2-3 recipe more or less.  Some of the materials were hard to measure like that.

The first vat was an aloe vat.  I ground up some aloe leaves, added indigo and lime.  The ph was around 12.3 on my ph meter.  This was the one that was hard to measure.  The results are below.  It looks weak to me so I will add some more aloe to see if that helps the pot.


001 002  003008

The second vat I used green tea.  As it is an antioxidant, I thought it might work.  Not really.  The ph is high enough but the indigo was clumped at the bottom.

006 005 004

I have added some fructose to this vat to see if that will revive it.


Alum acetate vs Potassium Alum sulfate + soda ash

August 10, 2013

This is an experiment with a yarn that is pearl tencel. As it is considered more of a cellulose yarn, I used two different cellulose mordants. The first was alum acetate. The recipe is from maiwa’s www site, The second recipe was 12% potassium alum sulfate and 15% soda ash. The latter recipe is derived from Liles. Both skeins were soaked in tannin. The soda ash skeins were darker after the mordant step. The soda ash must have interacted with the gall nuts. One set of skeins was dyeing in madder. The other set was dyed in q black. In both cases, the skeins dyes unevenly. The skeins mordanted with alum acetate dyed darker. The hand of the skeins is a little stiff, the washing soda skeins are a little better than the alum acetate as far as hand but they are more uneven in terms of color.

The reason for the two mordant choices is that in the past, I have had problems with the hand on a wool tencel blend with the alum acetate. A friend of mine experimented with other recipes and found the soda ash recipe improves the hand.


The darker skein is the one that was mordanted with soda ash


In this photo, the skein on the left is the alum acetate. The Indigo skein is for comparison.

Taos Wool Festival 2012 – Samples from Botanical Colors Workshop

March 4, 2013

These are samples from a workshop I took at Taos Wool Festival 2012 that was taught by Kathy Hattori.  We used a combination of the botanical colors liquid dyes and a woad and indigo pot.  Some of the samples are wool superwash, some are wool.  The cowl is knit from the non superwash samples.   The first sample in the card is an orphan – a sample of the 50% wool 50% silk from LaLana dyed with chamisa.  As it was from Taos and I purchased this year, I put it in the sample card.

cowl photo sample card twf 2 2012 sample card twf 2012


Piece knit with other samples – a pattern by Lee Meredith – Parallel Lines


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