Monday 28 April 2008

On silk yarn - what every weaver should know!

I was going to write about this very useful book a couple of months ago, I took the photo but didn't get much further than that. At the time, there had been a discussion on the Weavetech discussion list about identifying what type of fibre was used in a yarn by carrying out a burn test. This book includes burn test information.

It is:
Handbook of Textile Fibres, by J Gordon Cook B.Sc.,Ph.D.,
published by Merrow Publishing Co. Ltd, first published 1959, 2nd ed. 1960.

I found my copy at a secondhand book fair, and bought it because it looked useful, although I had not heard of it. My copy has parts 1 (natural fibres) and 2 (man made fibres) in a single volume, I just looked on the Abebooks web site and found that some of the copies offered are just part 1, or part 2, and that it seems to have gone on to a 5th edition (1984). Prices start low, at around £4.

This book is a superb reference book. It's a great book to dip into, or to look something up, but there's so much information in it that it's not the kind of book that it's easy to just sit down and read. Because of that, I'd had it a while before I really got to understanding and appreciating it's value. In fact, I do recall at one time wondering why I'd bought it! But I did buy it a few years back, some time before I started spinning and weaving. Now, I find it is invaluable.

Why? Well, for example, there are 35 pages about wool . There's a brief history of the wool trade in England then all you might want to know about wool production and processing, physical properties and behaviours, chemical structure and rather more besides.

For example, did you know that "Wool... can be curled by coiling it round a rod. If it is placed in boiling water and cooled it will remain in the form of a spring. It is acquired a permanent set."? This happens because water attacks wool keratin and can cause changes in the chemical structure. Did you know that as wool absorbs moisture it generates heat? And that it releases the water it has absorbed very slowly and gently, which means that you don't get sudden cooling?

There's also extensive information about insects that attack wool, about shrinkage and felting (what happens and why) about washing. Here's some information on washing wool - the ideal temperature is about 100 degrees fahrenheit / 38 degrees C, and the best technique for washing is a process of soaking and squeezing - avoid agitation, tumbling and stirring. And another notable fact - handknitted yarns benefit from a residual tendency to felt, helping the knitted garment to hold its shape.

There is similar information in the book about other fibres, so it's good to compare and contrast and for understanding the relative properties and uses of different fibres.

By now you will be wondering why on earth the title of this post is silk yarns!

Answer, it's because this is what I was looking up last week. I needed to find out about: the different types of silk yarn, how they are made, what their different properties are, what might make a good warp yarn.

I also referred to:
A Silk Worker's Notebook, by Cheryl Kolander, pub. Interweave Press 1979, revised edition 1985

Silk, Luther Hooper, Pitman's Common Commodities and Industries Series (1930's? no date given)

From Fibres to Fabrics, Elizabeth Gale, Mills & Boon Ltd., London, 1978 edition.

These are all good and useful books. Cheryl Kolander's book strikes me as rather a slim volume for everything she wants to include, and sometimes I wish she had taken more space and written more. It is a lovely guide book to have covering basic information of history and use, handspinning, caring for silk, and has appendices with notes on weaving and knitting.

Luther Hooper's book is about silk production, from the moth(s) that produce silk to factory processes, going through to weaving. It is a lovely and useful book, although I am writing more about the others today.

Elizabeth Gale's book is a text book, written by a textile designer, for use in schools and colleges, "to assist those who wish to know about textiles without going into the technology of the subject in great detail". It was this book sitting on my shelf that inspired my blog name!

From Cheryl Kolander, I learnt that there are two types of silk yarn, reeled and spun. The reeled yarns are "thrown". She says "throwing is the process of twisting the unspun filaments of reeled silk." Thrown silk produces fabrics "stronger and more durable than comparable fabrics of spun silk". She says the two most important types are organzine, a tightly twisted and plied yarn, and tram, which has only enough twist to hold it together and is used for weft.

She says that spun silk is comparatively modern, a means of making use of the waste from thrown silk, which had in former times been used as wadding to provide insulation. The machinery for spinning wool and cotton made possible the spinning of silk waste into yarn:

"Spun silk yarns go by many names, some refer to the fiber-length, some to the fiber's character, and some to the yarn's spin."

The list she gives includes tussah (wild silks), meche (soft, long staple, regular twist), shantung (slighty slubby), cord (twisted and plied), flourette (long staple, spun from combed fibres) bourette (short staple, spun from carded fibres of 1-2" length).

Elizabeth Gale says of spun yarn that "Long raw fibres are cut to a maximum length of about 30 cm and are spun as for worsted, and short lengths are spun like cotton."

I remembered Peg wrote recently about the behaviour of two different skeins of yarn she had dyed, one was oraganzine - so a high quality thrown yarn - and the other bombyx - possibly a spun yarn? This might explain very different behaviour, the two yarns are probably very different in construction and from very different fibre lengths.

I'd look after that organzine carefully, Peg. Cheryl's book tells me that "thrown silk yarns are rarely available to handweavers. This is partly due to their expense... partly due to the fact that thrown silk yarns are usually very fine, much finer than most of us are comfortable with."

Indeed, I have here my catalogue and price list from H.T.Gaddum & Co. Ltd, a specialist silk importer in Macclesfield, England, (tel: 01625 427666) generally regarded as the best source of silk yarns for handweavers in the U.K., and they offer only spun silks - which range from £40 to £64 (per kilo, excluding V.A.T. ) and textured silks.

(Another good source of interesting spun silk yarns is Texere Yarns, of Bradford, England.)

So, what about my little Handbook of Textile Fibres on the subject of silk? There's 20 pages, so it is not as easy to summarise as Cheryl Kolander's book. It even includes a short section on "spider silk"!

Looking at the types of silk yarn, however, thrown silk (the name coming from the Anglo Saxon word "thrawan" meaning to whirl or spin) is made from "multi-filament strands.. twisted together to form heavier threads", although sometimes weaving is done from the filaments as they are, without twisting them. I was interested to learn that the "natural gum, serecin, is normally left on the silk during reeling, throwing and weaving" because "it acts as a size which protects the fibres from mechanical injury". The weight of the woven fabric may reduce by a third when the serecin is washed out! The cloth before the serecin is washed out, which is dull in appearance, is known as "hard silk" and when dugummed as "soft silk".

The extra information about thrown silks in this book tells me that tram is made from two or three strands of silk, and could be low twist with 2-3 twists to the inch, or high twist with 12-20. It is of moderate strength. Oraganzine is very strong, 2-3 strands are twisted together and then the compound thread is twisted 9-30 times to the inch in the other direction. Very high twist yarns, 30-70 twists to the inch are known as crepe.

There's an interesting section on the spun silks:
"....the throwster is fortunate if he can make use of half of the available silk in filament form. The rest of the silk is unsuitable for reeling, and is know as 'waste silk".

"This waste silk is much too valuable to throw away, and it is used for making the yarns we know as "spun silk"......"
".....After dugumming... The silk is opened and loosened in a machine that delivers it in the form of a gauze-like blanket or lap. The fibres are then combed and sorted into length-groups, and then draw into rovings and spun by twisting so that the short fibres hold tightly together."

The section on silk ends, as with other fibres described in the book, by giving details of effects of sunlight, age, moisture, heat, chemical properties, electrical properties, effects of acids, alkalis and solvents.

Did you know...

- Silk can take up 1/3rd its weight in water without feeling wet to the touch,

- and wet strength is 75-85 per cent of the dry strength?

- It has less elastic recovery than wool, but better than that of cotton or rayon.

- Once stretched by 2% of original length, it will be permanently stretched.

- It will stand higher temperatures than wool, but decomposes quickly at 175 degrees C.

- It is a poor conductor of electricity, and gets a static charge in dry atmosphere.

- Silk is so costly that fabrics are often "weighted" with metallic salts to create artificial density, a moderately weighted silk could contain 25-50 per cent salt, heavily weighted 60 per cent. Weighted silks are not as strong and can deteriorate rapidly - e.g. perspiration will cause rot. But I don't think handweavers will be using this technique!!

Wednesday 23 April 2008

Using acid dyes on wool and silk yarns.

The dyeing I have done, before this month, has been entirely with natural dyes. I never intended to only use plants stuff and natural dyes, but the more I used these dyes the more things there seemed to be to explore. I love the natural dye colours. Living as I do surrounded by a beautiful landscape, the natural dye colours are the colours of the world I live in.

However, I must confess that I enjoy the bright colours of modern dyes as well and have been interested to read about the way Peg uses her own dyed yarns in her weaving. So, I did not hesitate when the opportunity arose to sign up for a "Rainbow Dyeing" workshop with the Alsager Guild of Weavers, Spinners and Dyers. Especially as the tutor, Janet, is ex-chemistry teacher and colour expert.

I chose to use a type of yarn I haven't worked with before - silk - and also some light grey Suffolk wool. I chose these partly because I thought most workshop participants would turn up with white fleece and wool yarn, and so I thought it would be interesting to use something different.

I bought a 100g skein of silk yarn, and needed 10g skeins for the workshop. I found this skein did not unwind well from my skein winder, so ended up working with it laid out on the floor, winding first into little balls that I could check the weight of on my scales. These scales are precision triple beam mechanical scales, accurate to 0.1g (they are designed for laboratory use) from Adam Equipment. I find them easy to use, and very useful for all sorts of things from weighing dye stuff to weighing letters to work out post charges.

Here are the skeins ready for dyeing, the grey wool seems to have come out looking darker than normal in this photo, but it gives you an idea of where I started from.
It seemed to take an age to put together all the bits and pieces I needed for the workshop - I was up past midnight getting prepared. The crumpled mess on the left is an old man-sized denim shirt, which is my favourite choice of apron. Other essential items included a measuring jug, old yogurt pots, rubber gloves, white vinegar, washing up liquid, paper towel, cling film, old newspapers, marker pen and plastic labels.
Glaubers salt, dyes, paint brushes, pans, steamers and microwaves, syringes were all provided.

At the end of the day, this is what I brought home:Oh what fun it was! I had missed a workshop last summer on immersion dyeing, this workshop was another technique. We laid out our skeins on sheets of cling film and painted dyes on to the yarn. I was interested to see that when one side was painted, and the yarn looked throughly coloured, when it was turned over the second side was mostly white. So, the painting needs to be careful and thorough.

The dyes we used were Kemtex acid dyes, and they were prepared in 1% soloution (i.e. 1g dye powder to 99ml water).

The yarn / fibres were prepared by heating to 65 degrees centigrade in water, then simmered 10 mins. For each of the 10g of fibre/yarn we added 1ml washing up liquid, 10 ml vinegar, and 10 ml glaubers salt. How easy it was to measure the liquids with a large syringe! It was also easy to measure the dyes. For each 10g skein we used 40ml of liquid, which could be dye plus water, or all dye. It could be one colour, or any number of colours; hence the need for several yoghurt pots to keep the measured amounts with different colours separate. I used two colours at a time, and I started of with a "medium" depth of shade (or D.O.S.) which required 10ml yellow plus 10ml water, and 10ml blue plus 10 ml water. The two colours were in separate pots, and I had two household paint brushes to paint the colours onto the yarn. The result is the lower of the two skeins in this photo. The blue colour is dominant, it behaved differently, running into the yellow to make green. The yellow just didn't seem to run into the yarn in the same way.

The above skein was the second I painted, using 20ml yellow (no water added) to 10ml blue with 10ml water. There was still a lot of greenish yellow, but I did get some patches that were clear yellow this time.

The painted skeins were wrapped in cling film, placed in a plastic "roasting bag" and popped into a microwave with a mug of water to steam. They were given 1 minute microwaving, then checked to make sure the bag hadn't ballooned up, and then a 2nd minute. To set the dye using a steamer pan on stove takes 15 minutes. When the package was removed, one end was unwrapped first and the tip dipped into water to see if the dye ran out. All my skeins past this test first time, and so could be rinsed and left to dry.

I tried red shades next. The bottom yarn in this picture was magenta and red, and the top is red and plum. Again, I noticed some colours were taken up better than others - plum was stronger than red, and the red was stronger than magenta. As people using wool yarns were getting more intense colours than I was obtaining on the silk, I stopped adding water and used all dye. I also noticed that the silk didn't hold as much liquid as wool, so that 40ml was a bit too much for my 10g silk.

On the wool yarn , however, 40ml liquid was just right. This yarn is dyed with violet and plum colours.One of the best bits of the workshop (apart from lunch - which was a real feast, everyone had brought a different dish for the table) was getting together around a table at the end of the workshop with all the dyed yarns on a table in the middle. Everyone talked about what they had done and what they had learnt. Now you just don't get that experience if you are trying something new at home. There were lots of different fibres used, lots of different ways the colours were combined, and many different lessons learned. I was particularly interested to discover that hairy fleece absorbed lots of dye - just the opposite of my experience using the silk. Also, to learn that a dyer who wanted a distinct emerald type green found that blue plus yellow gave a better colour than the prepared green dye. One or two of us had learnt to keep our gloves on if we didn't want coloured fingers! Oops! At least the colour I got on my fingers was red, so it didn't look too strange.

One last handy hint from this workshop: see above. We labelled our yarns with plastic labels made out of plastic milk bottles, and wrote on them in marker pen. It worked very well.

Footnote - in response to a query:
The treatment of the yarn in a saucepan of water with the glaubers salt, washing up liquid and vinegar was a pre-treatment. The purpose is to improve the dye take up. The pot with all these things in was heated gently to 65 degrees C, kept there for 10 minutes and then allowed to cool. The yarn was taken out and rinsed before we used the dyes on it, so it was only slightly warm still by the time we started to use dyes.

Monday 21 April 2008

Inkle warp

A couple of weeks ago I wrote about a problem with my inkle bands - the first few inches woven were uneven, especially at the edges.

I warped up the little loom again last week, thinking about this problem as I did so. I wind the warp around the loom first, and then put the heddles on (yellow threads in the picture below). The yellow heddles are restraining alternate threads, the un-restrained threads can then be raised and lowered by hand to create the shed to pass the weft thread through.
Putting these heddles on was creating uneven tension - why didn't I realise that before? The warp is a continuous loop - when I change colour I tie a knot and keep wrapping the thread around the loom. This means that uneven tension can be cured by working the warp about and moving it around the loom so the stresses settle out.

It worked perfectly. The picture above shows the first few inches of band I wove. I am so pleased to have fixed this little problem, all my inkle bands can be beautiful now. I could think about some more fancy weaving patterns. There are some lovely, more complex, designs that can be woven using pick up techniques. See the work of Tracy DeGarmo, Heather Heroldt, and Sara Lamb.

Monday 14 April 2008

Twill sampler

I put up my title for this post and then realised the first photo is not actually twill!

I put a warp on my loom of 12/2 cotton at 36 epi. The intention was to weave again some twill patterns I had woven last year at 24 epi. I wanted to do this because of an advanced twill workshop I followed with the Online Guild a few months ago for which I used the recommended sett of 36 and was amazed how different the cloth turned out.

So, why is this first photo of plain weave? Well, half way through the sampler, I was looking around me one day and saw a ball of fine spun singles wool that I didn't know what to do with. So, I picked it up and wove. First plain weave:
and then an undulating twill:

I really like the texture of the wool weft, and the soft look it gives to the fabric. Also, I like the amazing 3-d look of this undulating twill.

Another time, the yarn that came to hand was a cotton chenile. I had a go at weaving this in a horizontal pleat pattern (using 3-1 twill):

And now, here's a little gallery of some of my twills woven at 36 epi and 24 epi. I was fascinated by the difference it made. 36 epi gives a firmer cloth, and sharper definition to the patterns, but 24 epi gives softer fabric and flexibility. Sometimes a softer look to the patterns might be just what is wanted.

Each of these photos shows two cloths, both with 12/2 mercerised cotton warp and weft. The larger-scale pattern will be the one with sett of 24 epi, the smaller-scale has sett of 36 epi.

And here's another bit of something different, a couple of twills I tried from Anne Dixon's new Handweavers Pattern Book (published as Handweaver's Pattern Directory in the U.S.):

Saturday 5 April 2008

Cotton spinning, inkle bands, and my loom.

Last weekend I went to a workshop on Cotton Spinning, organised by the Hallamshire Guild of Weavers, Spinners and Dyers (based in Sheffield, England). Tutors were Carol and Peter Leonard. I already knew Carol a little as we are both members of the Online Guild of Weavers, Spinners and Dyers, and Carol has her own blog.

The Hallamshire Guild members were introducing themselves as soon as I walked in the door - what a wonderful community feeling there is in WSD guilds - and I soon enjoyed the feeling of being among new friends.

The cotton spinning was fun too! We used cotton sliver, and soon found it is easier to spin from if rotated between two closely held hands to open it up. We started with akha spindles, and once we had the hand of drafting the fibre and putting in plenty of twist for strength, then we moved on to long draft and supported spindles / takhli.

The beautiful akha spindle I used for the workshop was one made by Michael Williams (of Sheffield, who was actually there particpating in the workshop!). The takli was like those sold by Scottish Fibres, and PM Woolcraft. The support dishes were wood or ceramic. We found that the wood dishes seemed easier to use, because of the slight friction between the spindle and the wood.

In the afternoon, we applied the long draw technique to spinning with a charka or on a spinning wheel.

At the end of the day, I went home with a couple of new Bosworth Spindles, one in Zebra wood, weighing 14 grammes, which I am using to spin cotton, the other a heavier 35 gramme spindle in Pau Amarillo wood on which I am spinning wool.

Meanwhile, as regards weaving, I have just finished a twill sample (more on that another time) and once again have been using the thrums for inkle weaving. For the weft, I use a thicker dk cotton knitting yarn.

I find it difficult keeping the weaving looking even, as you can see in the photo, below. For some reason it gets easier towards the end of the band, I don't know if this is because I get into practice, or if there is some other reason. Any thoughts?
Before I put another warp on my loom, there is a problem to solve. Remember my new loom aprons? For the aprons rods I used slats from the hardware shop, sold for one of those old fashioned airing racks that hangs from the ceiling (we used to call it "the pulley" when I was a child, but now they are sold as the "sheila maid" and people seem to use that name). The slats seem to be of rubberwood, or similar, and they bend. I have tried to solve this problem before, without total success, see below.

This photo was taken a couple of weeks ago, at the end of weaving my twill sampler.

After a chat to my boyfriend, he went off to his workshop with a plank of beech wood, and came back with these:

They are larger section, and beech is a much stronger wood. I will be putting another sample warp on the loom soon and let you know how I get on.