Silk

In writing my bibliography I was startled to discover I had not written about a very, very good book that I discovered last year on silk. I did write on "Silk: what every weaver should know", with details of other books, so I must have purchased this particular book after I'd published that entry. I also wrote last May on the local history of silk spinning and weaving.

I was hunting high and low for information about silk as I wanted to know all about silk production so I could understand the yarns available, and also because I like to see the things in my life as part of a bigger picture. A yarn has more meaning if I know and understand: where does it start and where will it end?

Yes, I am turning philosophical now - I think it is important to know because we all make decisions that effect other people, and the sequence - what we acquire, how we use it, where it goes when we are finished - is a process that contributes to shape the world we live in.

I was also motivated by having bought some yarn of a quality that I thought was rather poor for expensive silk. More exploration showed I had bought relatively cheap, maybe this was part of the problem. It was full of knots and all wispy at the edges. I queried with the seller whether it really was thrown silk, as claimed, they told me they had it checked by an expert and and that it was (but there was no written report, so I don't know quite what the expert said)... and I thought thrown silk was made from long continuous filament and shouldn't have wispy ends protruding. So I hunted high and low on the internet to learn more.

This book which I found is about the big picture, it is:
Global Silk Industry: A complete source book, by Rajat K Datta and Mahesh Nanavaty, published by Universal Publishers, USA, 2005, ISBN 1-58112-493.
I found and bought it via Amazon.com, it was inexpensive - at a time when the dollar-pound exchange rate was more favourable!

The authors are well qualified. Rajat K Datta is a retired director of International and National Sericulture Research Institutes in India (author of 300 scientific and technical papers) and Mahesh Nanavaty has worked for over 30 years in the silk industry, in the USA and India. The foreword is written by Xavier Gavyn Lavergne, as Secretary General of the International Silk Association.

As regards the content of the book, the preface has this neat summary

"Here are gathered, indeed, the main information and anaylsis regarding the history of production and trade of this exceptional fiber, from the origins of silk to the 21st century, covering the important changes in the silk scenario notably in the course of the 20th centruy, which explain today's situation and enlighten the future."

So we have history, we have a chapter looking at silk in relation to other fibres, an overview of the global silk industry today, and several chapters on silk production. There are reports on current and developing technology, and on the uses and market / marketing of silk.

However, this is not a heavyweight textbook, it is a paperback, 352 pages plus appendices and I found it a good read. Not only that, it filled in many gaps for me, I'm happier now that I understand how to find the quality of silk, and type of yarns, I want to buy, and where my use of silk fits in to the big picture.

Thrown silk - and the Macclesfield Silk Industry

I've been lent a most readable history book, East Cheshire Textile Mills, published in 1993 by the Royal Commission on The Historic Monuments of England, now, sadly, out of print.

I live in the west of Derbyshire, close to the Cheshire border, and one of the mills featured is a watermill only 20 minutes walk from our house. This book brings together places and buildings I know with the story of the local textile industry, hence there is much to interest me.


WATER POWERED TEXTILE MILLS
The textile mills of east Cheshire came about because of water power - the streams and rivers running down from the pennine hills made mill machinery possible, and the first mills were built in the 1700s. The silk industry in this area pre-dates the cotton industry.

Silk throwing pre-dates the mills and was carried out in this area in the 1600s to meet a growing demand for luxury and fancy goods. However, the throwing techniques used were not capable of producing organzine for warp threads and until Italian methods of throwing (using water-powered machinery) were introduced in the early 18th century, only the lower quality tram thread (used for weft) was produced and organzine had to be imported from Italy.

The first mill producing organzine was built in Derby (in Derbyshire, not Cheshire) in 1704, on the banks of the river Derwent . It is thought that this was the first powered mill in England.

It was 1744 when Charles Roe, a button merchant, put up the first silk throwing mill in Macclesfield.


THROWN SILK PRODUCTION
So how was the tram thread produced before mechanisation? There's an amazing account taken from an 1841 Parliamentary enquiry:

"... He (the boy) takes first a rod containing four bobbins of silk from the twister who stands at his 'gate' or wheel, and having fastened the ends, runs to the 'cross' at the extreme end of the room, round which he passess the threads of each bobbin and returns to the 'gate'. He is dispatched on a second expedition of the same kind.... "

The twister's wheel was turned to twist the threads, and the threads then wound onto a bobbin. The room the boy ran up and down was between 25 and 35 yards (23 - 32 metres).

When I read this description, it fixed in my mind a clear understanding of what thrown silk actually is, and how / why it is different to a spun yarn.


THE SPINNING OF SILK THREAD
The process of producing thrown silk - reeling and winding silk from the cocoon, cleaning and throwing - was inefficient and the waste silk from the process was estimated in 1765 to be around half of all the silk. As silk was so valuable, and as the industry increased, there was a great need to find ways of using this silk.

Here there is a link to the cotton industry (for which nearby Manchester and Lancashire are famous).

Machinery created for cotton spinning was adapted for silk. To begin with, the silk was cut into short staples, 25-50 mm in length, which could be spun on cotton spinning machinery.


A HIGHER QUALITY SPUN THREAD
Then Gibson and Campbell of Glasgow obtained a patent in 1836 for a machine for the spinning of long staple length silk, up to 250mm length. This enabled production of high quality yarn from the better quality silk filament waste. Silk spinning became established in Cheshire, in mills at Macclesfield and Congleton, by the early 19th century.


MACCLESFIELD
Macclesfield, Cheshire had not only mills for production of silk thread, but also was a centre for weaving. During the 18th century there was a thriving handloom industry, with weavers either working independently or as outworkers. For example, in 1818, one silk manufacturer, Henry Critchley, employed 140-160 weavers. 50 worked at his factory premises and the rest were outworkers, weaving in garrets. Garret houses were specially built with the top (third) storey having large windows to make good workshops, and two dwelling floors below. Some of the houses were built in terraces with one long garret above several dwellings. It is easy to spot many of these distinctive houses today.


TO LEARN MORE..
If you have an opportunity to get there, you will find some excellent museums in Macclesfield.

The publications in the late Ralph Griswold's Online Digital Archive include Silk by H. Gaddum of Macclesfield and Luther Hooper's book, Silk: Its Production and Manufacture which I mentioned in my previous post. Use this link for the publications on silk.

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!!

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.