Jacquard

“Choose any subject you would like to write about…” that is the object of the A to Z Challenge, and thinking of things that interest me is not a problem for me, but choosing a subject not only to write about, but to write in a way that other people will catch my interest – that is the real challenge! This year I turn to a subject, close to our skin if not our hearts, and yet, again, I wonder if this subject will get some people past the title on the list – dismissed as niche? For this year, my theme is What We Wear – Fabrics and Fibres

Almost as soon as the art of weaving or knitting fabrics was mastered, then the possibilities of creating decorative effects with the craft, blossomed. Mary Schoeser in her World Textiles – A Concise History¹, says of the period between 3000BC and 400BC, that although normally categorised historically as the Bronze and Iron Ages, they might equally be termed the Dye and Loom Age. Whilst it is true that iron shears were necessary to shear livestock for fibres to make fabric, the technological and chemical developments are at least as impressive and important as those in Metallurgy.

Dyeing is the simplest of ways to decorate a fabric and if the fibres/yarns are dyed first, before weaving, then the second way of producing decorative effects becomes possible by using different coloured yarns in the same piece of cloth – think stripes, plaid. Tartan not to mention fabrics that use different colours for warp and weft and that is before you use the lifting of some selective warps to give a design. There is alternating stitch patterns in knitting or weave types in weaving, introducing thicker threads – the variety of ingenuity is incredible!

Beyond dyeing, there are ways of embellishing fabrics such as embroidery, adding in beads, using a fabric as a base for some other technique – lacemaking, needlepoint tapestry, hooking or rag-rugging, but let’s start with the advances in chemistry brought about by dyeing.

There are three types of Dye which are each suitable to be applied to different types of fibre using different chemical methods:-

Reactive Dyes: Primarily used for cellulose (plant derived) fibres such as cotton, linen and semi-synthetics like rayon, where the dyes form strong covalent bonds with fibre hydroxyl groups (-OH) resulting in high, wet, fastness of colour.

Direct/Acid dyes:- Utilise hydrogen bonding and Van der Waals forces,  to attach to proteins (animal derived) – amino acid groups attract dyes through ionic interactions.

Disperse Dyes:- Non-water-soluble dyes used for hydrophobic synthetic fibres like polyester, dyes which are absorbed as a solid solution under high heat and pressure.

Of course, the early dyers didn’t know the meaning of all this chemistry, they discovered things empirically, no doubt early results were a result of accidental contamination, but the dyer’s vats became the crucible for chemical experimentation. Other chemical factors which were discovered and deployed in dyeing include:-

pH Adjusters: Acids or bases (eg. Acetic acid, urine, caustic sods) crucial to initiate bonding of dyes to fibres.

Electrolytes: Salt (NaCl or Na₂ SO₄) used to force dyes out of solution and onto the fibres

Mordants: Metal ions (Aluninium, copper, iron) which act as a bridges between natural dye molecules and fibre – these illustrate how empirical learning can occur as simply conducting dyeing in different containers made of different metals would produce more or less effective results.

Let’s look at just one dyeing process – that of wool, to understand what happens…

The illustration shows the three stages of wool dyeing, firstly the Dye Approach, in which wool is added to the dye solution and heated up. The dye molecules immediately coat the wool surface but water then moves into the fibre making it swell up and allowing the dye to better penetrate the fibre. Dye Migration – the dye molecules move in and out of the fibre and even themselves out, migrating from darker to lighter areas until an equilibrium of molecules both in the wool fibres and the solution is reached. Dye Fixation – the wool is temporarily removed form the dye bath and a mild acid is added such as citric acid – a mordant that lowers the pH of the bath so that when the wool is returned to the dye bath, the dye molecules are forced to bond with the wool fibre – the bath is heated slightly more and “cooked” for another 60 minutes until the bonding has occurred both on the surface and inside the wool fibres.

Textured Weaving Effects are the next simplestway of decorating fabric and we have already encountered the Twill Weave which has produced such classic fabrics as Denim, a tough working fabric which in terms of dyeing, may be warp dyed, undyed, or dyed after weaving – more of denim when we get to working fabrics… but corduroy, cambric (basket weave), and Georgette (made with highly twisted yarns) are all examples of textured weaving.

Next, patterns may be woven in – Damask, for example, which at its simplest, achieves patterns with a limited or single coloured yarn by varying the weave texture between satin and plain.

Another fabric in which highly patterned effects are woven in on the loom, is Jacquard – using a Jacquard loom. Producing tough, brocade like fabrics often used for furnishing and curtains.

Once you start introducing different coloured yarns you are into a world of plaids and tartan before you even start on more complicated weave patterns like houndstooth.

Troon Houndstooth

This example of houndstooth clearly shows the classic, two-colour weave pattern.

Once a fabric is finished, in can then be embellished with further stitched patterning – Embroidery:- The word embroider has come to mean the addition of anything to anything in order to make it more attractive, detailed, or meaningful – but originally it meant stitching additional threads onto a material. There is so much to say about Embroidery that I am going to give it, it’s own slot tomorrow and Printing on fabrics will be covered when we get to “P”…

P.S. As Anne M. Bray points out in the comments below, I misssed out Ikat – one of the oldest fabric dyeing techniques – in Ikat, either the warp threads or the weft threads, or both which is the most complex, are bound together in bundles pre-weaving, and treated with wax in patterns that resist the dye and create a pattern in the weave. the patterns have a blurry quality which is quite different to patterns printed on after weaving…

Also from Anne – this excellent link to her SpyGirl: Know Your Plaid…

The decoration of fabric merits n A to Z of its own, but I will leave it there and cover a few “D” fabrics.

Damask Fabric with the pattern woven in. It is reversible, hardwearing and usually made with cotton, silk or linen.

Dimity Collective term for figured cloths of harness loom decorated with designs and patterns. It is a strong cotton cloth with various stripes and illustrations. Dimity is bleached or washed after looming, less often dyed—unlike fustian, which is usually dyed.

Dobby (see also Piqué) a woven fabric produced on the dobby loom, characterised by small geometric patterns and extra texture in the cloth, The warp and weft threads may be the same colour or different. Satin threads are particularly effective in this kind of weave as their texture will highlight the pattern.

Double cloth is a lightweight, sheer cotton fabric, having at least two warp threads thrown into relief to form fine cords. Chiefly, dimity is fashioned into white bed upholstery and curtains, though it is occasionally imprinted with a colourful pattern. Dimity was historically made of silk or wool; however, since the 18th century, it has been woven almost exclusively of cotton.

Double Crepe Heavy textured fabric that is drapey, usually made with silk and wool fibres

Double Georgette Heavy denser version of georgette, characterised by its texture and transparency.

Duchesse Satin weave construction it is a structured cloth characterised by its high shine on one side and matte on the reverse

Dupioni a Plain weave cloth, is characterised by the slubby effect created when raw yarns are woven with more refined silk yarns.

1. World Textiles by Mary Schoeser – A Concise History, Thames & Hudson world of art 2003 pp. 28

I compiled a list of as fabrics, fibres and related items as possible (278 items), from several sources, the most comprehensive of which was Wikipedia. Since there are only 26 letters in the alphabet, I could not write in detail about every instance so I have taken snippets of text for the brief descriptions and linked to the source in the name of the item. I am indebted to all the contributors to those Wikipedia pages and the depth of knowledge to be found there…