Textile Tidings

It's taken a while but I've finally got back into my account! I will endeavour not to forget my password again.

So - what is the title about then? Well over the years when I've gone to Guilds and Museums doing my demonstrations and talks about "The Life and Times of the Mediaeval Dyer" or Roman or Tudor or Geargian and now World War 1, I have frequently been asked whether I have written a book with all the information in that I've been talking about.

The answer has been always "No!" However it has occurred to me that a compilation of period textile "facts" would help me no end - getting older and the brain being slow, if everything was written down in one place then it would be easier to refer to, so I've decided the time has come to start this compilation.

The title will be Textile Tidings hopefully a mix of interesting little facts about anything to do with dyeing, spinning, weaving, fibres, sheep, silk, etc, etc.In the paper version all references, primary sources etc will be annotated with the "fact" so it can be verified.

However I also thought it would be fun to put facts out into the big wide world as a bit of a game. So on twitter and facebook if you see #TextileTidings please join in and say what you think something might be or when it was or what it was.  I won't be able to do one every day - we don't always have the use of computers and phones when working (Mediaeval Dyers didn't have them!!) But they'll be out there as often as possible!

Watch out for #TextileTidings!

Cream of Tartar

So...........what does the name conjor up for you? For me it means the white powder that you buy in tubs from the bakery section of a Supermarket or Grocers store. I have no idea where the name "cream of tartar" comes from, but  historically, it was the "leys of wine" the powdery sediment found on the walls of wine cellar vats. Then it was given the name "Argol" and it could be red or white depending on the colour of the wine it came from!

 There appear to be many names for the chemical - the commonest I have found are Potassium Hydrogen Tartrate or Potassium Bitartrate, but you can also find monopotassium tartrate, potassium acid tartrate,

[R-(R*,R*)]-2,3 Dihydroxybutanedioic Acid Monopotassium Salt, Potassium (2R,3R)-3-carboxy-2,3-dihydroxypropanoate, and more.......!

The chemical formula can be written KC₄H₅O₆ 

or even

C4H4O4 (OH) (OK)

Its CAS  number is 868-14-4 (One of the commonest classifications to stop confusion between chemicals)

CB number -CB7854493

formula weight:188.18
E number - E-336(i)

  It is the mineral acid salt of Tartaric Acid and probably best known for its stabilizing properties when making meringues. It is a component in Baking Powder and also a chemical buffer.

So I can now see you wondering what this post is all about!

Many dye recipes both historical and modern recommend the use of Argol  or Cream of Tartar as an addition to alum in the mordanting process, it is there to assist the alum in mordanting wool with salts of Aluminium, Chromium, Iron, Copper and Tin. It is said to improve the permanence, fulness nad brilliance of the ultimate colour. For the chemists amongst you this is surmised to be due to the double decomposition of the tartrate and the mordanting salt, the mineral acid of the latter combining with the potassium of the tartrate and the metallic hydrate with tartaric acid, (it is also possible that a double salt is formed).

Given all the above information I am struggling to understand why several dye retailers in the UK make a claim that the Cream of Tartar sold for catering is a substitute chemical not suitable for use as the mordant assistant.

So what is this substitute? I cannot find it - is it the same product but using one of its other names?

For my own peace of mind I have comtacted Dr Oetker and Tesco both of whom are very clear that the product they sell under the name Cream of Tartar is CAS number 868-14-4 Potassium Hydrogen Tartrate (etc, etc) I have their replies in email format so if you wish to see them I am happy to forward on - or feel free to contact them yourself.

I feel so strongly that we should be able to buy the product we want under the name that it is known by that I would like to find out more on the subject of this "substitute" used for catering. Maybe if there is a substitute we should be considering approaching Trading Standards to get the name used as it should be and another name for the alternative!

What can have coloured my silk?

I have just prepared a variety of silk fibres and yarns ready for dyeing. There are several winter markets coming up so I thought I ought to get started - but without the usual panic and rush!

Maybe this was a bad idea! ALL the fibres and yarns were Mulberry silk so white rather than cream or caramel coloured. I scoured them all first - but in separate pans as I didn't want the fibres attaching themselves to the yarns.

 I had already mordanted alpaca and romney so the mordant was an exhaust bath being re-used, it had had alum and cream of tartar in (hopefully taken up by the wooly yarns) so I added a different proportion of alum and cream of tartar for the silks. The liquid was CLEAR, absolutely no sign of any colour before I entered the silk. The silk was still white before being entered.

The liquid was heated to about 45 degrees and then left for a day - I like the mordant to have a good length of time with the fibres! When I took the lid off to srain out ready to use again I had something of a shock! 

All the fibres had changed colour to a lovely shade of peach! The liquid has remained colourless - hopefully you can see that from the yarn picture. The mordant bath is stainless steel and there is nothing unusual about the alpaca and romney that came out before. (The green you can see is the tags I use for labelling my yarns - and no, none of the ink has come off either!)) I am sure there is no iron contamination and although I do sometimes add in tannin when mordanting silk (correct historically) there was none present here.

The white tub shows the silk caps that have been taken out of the bath - they really are very pretty, but what can be the colour?

I haven't yet tried to dye any of the fibres - that will be the next interesting challenge,

Has anyone had a similar experience - or any suggestions? I'll let you know how I get on with the dyeing in due course!

Cellulose Mordanting

When I first started on my path as a natural dyer I wanted to work with silk. I was particularly interested in making embroidery silks that I could use for 17th century reenactment. Very soon after starting I came across references to using linen as the ground for the embroidery and wondered if I could dye the linen base.

The learning experience is unusual with natural dyes, you start off thinking "oh this is easy" then you progress to the " I know that already" stage, and then you begin to realize that the subject is so huge that you can only scratch the surface in a lifetime. I have been at that stage for quite a while, but I do feel that having concentrated on dyeing silk and linen I am pretty competent at getting a good colour on those particular fibres. I would never describe myself as an expert - ever- after all "an ex is a has been and a spurt is a drip under pressure" and who would want to be described thus? But I digress as usual.

The point behind this post is that I have been doing some experimenting with cellulose mordants, the results I have obtained so far (and I do accept that it is a very simplistic start) have made me realize that I need to do some serious study here and ultimately write an academic paper on it, so please excuse me, but I am going to put a copyright on this post, in preparation for that final paper!

Coming from an historical perspective I have always used the alum tannin mordant method for linen (and cotton). I use oak galls as my tannin source, rather than tannic acid, to appease the environmentalist in me, I may have to adjust proportions accordingly, but I follow given recipes. My first reference when I started on cellulose was Gill Dalby's book natural dyes for vegetable fibres. She was an amazing lady who did much to promote natural dyes - and worked with the environment in mind, it is from her book I get the 8% alum and 7% cream of tartar recipe for protein fibres. Jim Liles The art and craft of natural dyeing was my next book and I learned about using aluminium acetate as a mordant from him. (both are well stained as you can imagine!) When I started using the Earthues extracts I thought I'd try out the commercially produced aluminium acetate as Michelle Whipplinger is so pro using it, it's certainly quick and easy and is very good if you have a mixed fibre combination like hemp silk.

In my own sweet little world though I wasn't so sure, so I decided to do a simple experiment. I broke a 100g hank of cotton (my wonderful new organic cotton boucle, which will be available very soon!!!) into smaller hanks of even size. Wetted them out for a couple of days first and then scoured them with washing soda and detergent keeping them all together. I then put 2 into an aluminium acetate mordant and 2 went through the alum and tannin method of mordanting. After rinsing them well I dyed 1 of each in madder and 1 of each in cochineal extract. The only thing that was different about the preparation was the actual mordant. Now look at the results! The alum tannin has taken the dye much more intensely for both dyes. I have not cheated here, it was a straightforward simple experiment.

Based on what I've seen so far, I think I will continue to use the older method for now - but as I get more into the research I'll keep you informed - and in the mean time I'll continue to stock aluminium acetate powder in my shop!!!

© Debbie Bamford, May 2009