Preamble
For your convenience I have listed below other posts in this series:
Diversity of African Textiles
African Textiles: West Africa
Stripweaves (West Africa) - Part I
Stripweaves (West Africa) - Part II
Stripweaves (West Africa) - Part III
Stripweaves (West Africa) - Part IV
Djerma Weaving of Niger and Burkina-Faso
Woolen Stripweaves of the Niger Bend
Nigerian Horizontal - Loom Weaving
Yoruba Lace Weave
Nigerian Women's Vertical Looms
The Supplementary Weft Cloths of Ijebu-Ode and Akwete
African Tie and Dye
Tie and Dye of the Dida, Ivory Coast
African Stitch Resist
Yoruba Stitch Resist
Yoruba: Machine-Stitched Resist Indigo-Dyed Cloth
Yoruba and Baulé Warp Ikat
Introduction[1]
West Africa, stretching southwards from Mauritania to Sierra Leone and then eastwards along the Bight of Benin to the Nigerian border with Cameroom, is in many respects the heartland of African textile production.
A cap maker from Kano (Northern Nigeria).
Indigo dyeing is practised to a greater or lesser extent in both the coastal regions and further inland. Resist techniques such as tie-dye, stitched and folded resist, wax batik and starch resist are common modes of surface decoration.
A young tailor sewing finely woven Ewe cloth (Ghana).
Narrow strips from 2.5 cm (1 inch) wide to 45.70 cm (18 inches) wide are woven by men throughout the region to be sewn together, selvedge to selvedge, to form garments for men and women.
Nigerian women wearing a variety of body wraps, some hand-printed and others machine printed.
Cotton is the main textile, though in the not too distant past raphia (the dried stripped leaves of the raphia palm) was in widespread use. Undyed wild silk is spun in Nigeria, both for embroidery and weaving. A broad upright loom is used by women to weave plain or warp-stripped cloth in southern Nigeria.
An Ashanti weaver weaving strips for kente cloth.
West Africa is by no means cut off from external influences. Kano, the ancient trading city of northern Nigeria, was visited by the noted Arab traveller Ibn Battutah in the 14th century. He remarked upon the indigo dye-pits of Kofor Mata, which nearly seven hundred years later are still in use.
Spindles of hand spun cotton (Mali).
The whole region is greatly influenced by two major world religions, Islam and Christianity. From the 11th century on, Islam was adopted via merchants from the caravan routes in North Africa, often for the practical reason that it made trade easier if both parties conformed to the same moral, religious and ethical code.
Wodaabe woman's embroidered cotton blouse (Niger).
Christianity was a relatively new comer, arriving in coastal regions with the Portuguese caravans that sailed around Cape Verde in the 12450s and landed by the Gambia River. Over the next five centuries Christianity spread along the coast, and at the end of the 19th century, inland, as British and French colonial power penetrated into the hinterland.
Glazed, indigo dyed Tuareg veil from Kano (Nigeria).
It is well known that the European traders - the Portuguese, soon followed by the British, Dutch and French and even the Brandenburgers and Danes - were attracted by gold, ivory and slaves. A vast trade arose often based on the classical triangular pattern of consumer goods going from Europe to the West African coast, slaves to the Americas, and rum and sugar back to Europe.
Tuareg mat of leather-bound reeds (Mauritania).
There were many variations on this trade, with products often coming direct from North Africa to West Africa, but the essentials of the trade remained the same. European and North African fabrics were major trading items on the coast.
Tuareg leather grain bag with painted lucky designs.
In addition, locally woven cloth was brought to be traded further along the littoral. It is important to mention specially made cloths such as the Pano d'okra woven by enslaved weavers on the Cape of Verde islands, which was so desirable and standardized that they functioned as money units.
Masquerade costume of grass-netting (Cross River, Nigeria).
Local production on the coast and in the near interior was stimulated by external trade, but in the hinterland, the adoption of Islam by the courts, rich merchants and others of influence had a more profound and long-lasting effect.
Tuareg embroidered panel (Central Sahara).
On the humid coast and in the hot dry interior, there is little need for protective clothing. However, with the introduction of Islam and so with its requirements for male, and in particular for female modesty it engendered a vast market for woven cotton cloth.
Tuareg painted leather cushion (Mali).
The wide shirts, trousers, and head-dresses were worn, not only by men who converted to Islam, but also by non-converts wishing to emulate the prestige of the Muslim community, who simply adopted their attire, but not necessarily their religion.
Strip-weave (Burkina-Faso).
Women conformed to the strictures of the new religion by adopting a range of voluminous wraps. Similar requirements of modesty were demanded by Christianity, but as this religion arrived comparatively late, they were often met from imported, rather than locally woven cloth, though most local needs came from local sources. The requirements of the two world religions stimulated local production of mainly strip woven cloth.
Painted Senufo strip woven cotton cloth (Ivory Coast).
The origins of creating a cloth by means of sewing strips together (selvedge to selvedge) are obscure, though there are both Asian (Uzbek Gudgeri) and North African (Berber flat weaves) precedents. Whether strip weaving is an adaptation of a technique that crossed the Sahara or is indigenous to West Africa is a matter of speculation, though evidence from the caves of the Bandiagara escarpment in Mali suggests it was practised in West Africa as early as the 11th century.
Picking indigo leaves for dyeing (Oshogbo, Nigeria).
It is not known how long the Fulani of Niger Bend have been weaving their woolen strip weaves, but as they are of Berber origin it is highly likely that they absorbed influences such as weaving technology from North Africa.
Skeins of wild silk for sale in Kano market (Nigeria).
By the 18th century complex strip weaves were being created in Kong in the present-day Ivory Coast. The neighboring Ashanti were at the same time creating a powerful kingdom based on gold around the city Kumasi. The wealth afforded by the gold trade enabled the Ashantahene (i.e. the king) and the Ashanti court to commission sumptuous and densely patterned strip weaves from the main source for royal textiles, the weaving village of Bronwire. The Ewe, located in south-eastern Ghana and Togo, and also the Yoruba of Nigeria, are very sophisticated strip weavers. Nigeria is also home to the vertical loom, on which women weave.
Spindles of handspun cotton and indigo dyed veils wrapped ready for sale in Kano market (Nigeria).
Indigo dyeing is one of the main means of coloring cloth in West Africa. The deep-blue hue is esteemed from the Senegal river down to the Cameroon border. Lonchocarpus cyanescens is the main plant for indigo dyeing. Various methods are used to prepare the indigo: either fresh leaves are steeped in wood ash lye vats or in deep pits, covered with lids that are set into the ground; or balls of dried leaves are used that were kept back from the harvest or acquired through trade.
A Hausa shopkeeper selling synthetic indigo balls (Keno, Nigeria).
Indigo cloths and clothing are still very popular, whether dyed in natural or synthetic indigo. However, it is mill-woven cloth, either locally made or imported that provides the bulk of everyday wear. Western models of clothing, often with regional modifications, are in vogue for both women and in particular for men.
A Hausa trader selling indigo-dyed veils (Kano market).
Two factors help to preserve the African handcrafted cloth making tradition. First, national cloths are still deemed essential for change-of-life ceremonies in general and for funerals in particular. Second, cloths such as bogolanfini mud cloths of Mali became fashionable in the West, which in turn influenced the local urban élite. African weavers, dyers and embroiderers will continue to produce fine cloth as long as there is a local market for them. Standards will decline if craftspeople have to rely on export orders and tourist-orientated production. The textiles required for the traditional change-of-life ceremonies will, it is hoped, keep traditional textile producers in steady work for many years to come.
A Nigerian village trader selling handwoven cloth.
Reference:
[1] J. Gillow, African Textiles, Thames & Hudson Ltd, London (2003).
Preamble
For your convenience I have listed below the other post in this series:
The Art of Costuming - Historic (Part I)
Introduction[1]
Ever since Adam's fig leaf human beings have fabricated their own clothing, not as a protection against the heat and cold nor to ensure modesty, but more importantly to enhance their appearance. Functionality has often taken second place to adornment.
Ceremonies have also played a vital role in determining dress. Whether it is body paint or specially made garments for special ceremonial occasions, whatever is the motivating factor, human imagination has no boundaries.
Aboriginal women ceremony in Australia.
Costumes also play other functions such as designation of rank and/or office as in the military, police, fire brigade and even in religion.
Pope Francis gives final blessing at Cardinal Law's funeral.
The differentiation in gender also plays an equally profound role in determining the ultimate shape of all things worn.
A man and woman's modern Octoberfest costumes.
Each of us practice this art: whether we want to attract, defend, conform, challenge and insult - we can do so by dressing appropriately, inappropriately or within our age or outside of our age, and whatever the choices we make in order to get a reaction or lack of a reaction we want, what we wear says a lot about us.
This post will explore the art of costuming in a historical context.
The Art of Costuming - Historic (Part II)[1]
The past decade has seen the emergence of a new art form, namely costuming. It is not the costuming of the stage or the cinema, nor special event costuming such as Halloween. It is not necessarily the wearable art of the galleries, although much of the work is so well crafted it is considered as such. It is not a static costuming displayed in museums on mannequins. This new art of costuming is dynamic and although it is on display it moves because it is worn by human beings.
Imperial Army Officer, Germany, ca. 1480.
Design and Construction: Elizabeth Pidgeon and Carl Ontis.
Model: Carl Ontis.
Photograph courtesy of Stephen Jacobson.
Lady Calitha.
Design, Construction and Model: Barb Schofield.
Photograph courtesy of Linda Sweeting.
The Legacy of Power.
Design and Construction: Barb Schofield and Mary Hudson.
Models: Jan Finder, Laurel Cunningham-Hill, Mary Hudson, Barb Schofield & Richard Hill.
Photograph courtesy of Stephen Jacobson.
Elizabethan gown from the wardrobe of Lady Sibyl Whitaker.
Model, Design and Construction: Jwlhyfer de Winter.
Photograph courtesy of Stephen Jacobson.
Mary Shelley's Day Dress and Mary's Pelise-robe.
Design and Construction: Jwlhyfer de Winter.
Models: Jwlhyfer de Winter and Kira Lentaigne.
Photograph courtesy of John Williams at Mary Shelley's mother's grave in Camden Town.
Renaissance Wedding Regency Costume.
Model, Design and Construction: Jwlhyfer de Winter.
Photograph courtesy of John Williams at Audley End House, Essex.
Thrift store fantasy Rococo Masquerade.
Model,Design and Construction: Jwlhyfer de Winter.
Photograph courtesy of Barron Scott Levkoff.
Ophelia Dress; a pre-Raphaelite gown.
Model, Design and Construction: Jwlhyer de Winter.
Photograph courtesy of John Williams at Kelmscott Manor, Oxfordshire.
Note: Former home of William Morris and Dante Gabriel Rossetti.
Reference:
[1] The Costume Maker's Art, Lark Books, North Carolina (1992).
Introduction
Art Quill Studio is the Education Division of Art Quill & Co Pty Ltd. My name is Dr Ellak I. von Nagy-Felsobuki and I'm CEO of the parent company. Marie-Therese Wisniowski is a Director of the Company and head of its sub-division Art Quill Studio.
The parent company, Art Quill & Co Pty Ltd, also publishes books, namely artist printmakers' books (e.g. Not in My Name) as well as problem solvers (e.g. Sudoku Solver) and fiction novels (e.g. 4 Steps to Freedom by Kalle Gayn). Some of these books can be directly bought from Art Quill & Co Pty Ltd, whereas others have a distribution company which supplies bricks and mortar bookshops as well as online bookshops with our published books (e.g. Kalle Gayn, 4 Steps to Freedom).
The legend under each book title will direct you to where you can purchase the printmakers' books.
Marie-Therese Wisniowski's Artist Printmakers' Book - see Not in My Name.
Limited Edition: A total of 10 editions only, five of which are held in the collections of: University of Queensland Library (6/10), National Library of Australia (7/10), University of Sydney Library (8/10), State Library of New South Wales (9/10) and NSW Parliamentary Library (10/10).
Recommended retail price: AUstralian Dollar (AUD) $1550.00 (plus shipping).
Editions for sale: 2/10, 3/10, 4/10 and 5/10.
ISBN 0 646 42979 5
Online sale currently available from Art Quill & Co Pty Ltd.
To purchase this limted edition printmakers' book please email: admin@artquill.com.au
Marie-Therese Wisniowski's Artist Printmakers' Book - see Beyond The Fear Of Freedom.
Limited Edition: A total of 15 editions, seven of which are held in the collections of: Columbia University, East Butler Library, Rare Book & Manuscript Library, New York, (USA) (9/15), Beau Beausoleil (USA) (10/15), Department of Art & Design, University of Western England, Bristol, UK (11/15), The National Library of Australia (12/15), State Library of NSW (13/15), University of Sydney Library (14/15) and NSW Parliamentary Library (15/15).
Recommended retail price: AUD $2,000 (plus shipping).
Editions for sale: 2/15, 3/15, 4/15, 5/15, 6/15, 7/15 and 8/15.
ISBN 978-0-9873013-7
Online sale currently available from Art Quill & Co Pty Ltd.
To purchase this limited edition printmakers' book please email: admin@artquill.com.au
The company has recently published a puzzle solver that is available for purchase from the company.
Dr E I von Nagy-Felsobuki, The Sudoku Solver.
Recommended retail price: AUD $14.99 (plus shipping).
ISBN 978-0-9873013-1-4
In the collection of the following libraries: National Library of Australia, University of Sydney Library, State Library of New South Wales and NSW Parliamentary Library.
Online sale currently available from Art Quill & Co Pty Ltd.
To purchase the solver, please email: admin@artquill.com.au
The company has recently published the first novel in the 'Magrete' trilogy titled - '4 Steps To Freedom.' The novel has been set in a historical context in Germany between 1935 to 1949.
Kalle Gayn, 4 Steps to Freedom (Front Cover).
Recommended retail price: AUD $24.99 (plus shipping).
ISBN 978-0-9873013-2-1
In the collection of the following libraries: National Library of Australia, University of Sydney Library, State Library of New South Wales, NSW Parliamentary Library, East Gippsland Shire Library (Vic), Monaro Regional Libraries (Bombala, NSW) and Cessnock City Library (NSW).
Distributor: John Reed Books.
It can be ordered via a retail bookstore such as booktopia or directly from the distributor: John Reed Books.
The company published in 2020 Kalle Gayn's second novel in the 'Magrete' trilogy titled - 'Reign of the Mother.'
Kalle Gayn, Reign of the Mother (Front Cover).
Recommended retail price: AUD $24.99 (plus shipping).
ISBN 978-0-9873013-3-8
In the collection of the following libraries: National Library of Australia, University of Sydney Library, State Library of New South Wales and NSW Parliamentary Library.
Online sale currently available from Art Quill & Co Pty Ltd.
To purchase this novel, please email: admin@artquill.com.au
The company published in 2021 Kalle Gayn's third novel in the 'Magrete' trilogy titled, 'A Phoenix Rises.'
Kalle Gayn, A Phoenix Rises (Front Cover).
Recommended retail price: AUD $24.99 (plus shipping).
ISBN 978-0-9873013-4-5
In the collection of the following libraries: National Library of Australia, University of Sydney Library, State Library of New South Wales and NSW Parliamentary Library.
Online sale currently available from Art Quill & Co Pty Ltd.
To purchase this novel, please email: admin@artquill.com.au
Kalle Gayn's - the 'Magrete' trilogy: 4 Steps to Freedom, Reign of the Mother and A Phoenix Rises.
Recommdend discount price for the purchase of the trilogy set: AUD $60.00 (plus shipping).
To purchase the trilogy as a three novel package, please email: admin@artquill.com.au
Preamble
This is the ninety-eighth post in the "Art Resource" series, specifically aimed to construct an appropriate knowledge base in order to develop an artistic voice in ArtCloth.
Other posts in this series are:
Glossary of Cultural and Architectural Terms
Units Used in Dyeing and Printing of Fabrics
Occupational, Health & Safety
A Brief History of Color
The Nature of Color
Psychology of Color
Color Schemes
The Naming of Colors
The Munsell Color Classification System
Methuen Color Index and Classification System
The CIE System
Pantone - A Modern Color Classification System
Optical Properties of Fiber Materials
General Properties of Fiber Polymers and Fibers - Part I
General Properties of Fiber Polymers and Fibers - Part II
General Properties of Fiber Polymers and Fibers - Part III
General Properties of Fiber Polymers and Fibers - Part IV
General Properties of Fiber Polymers and Fibers - Part V
Protein Fibers - Wool
Protein Fibers - Speciality Hair Fibers
Protein Fibers - Silk
Protein Fibers - Wool versus Silk
Timelines of Fabrics, Dyes and Other Stuff
Cellulosic Fibers (Natural) - Cotton
Cellulosic Fibers (Natural) - Linen
Other Natural Cellulosic Fibers
General Overview of Man-Made Fibers
Man-Made Cellulosic Fibers - Viscose
Man-Made Cellulosic Fibers - Esters
Man-Made Synthetic Fibers - Nylon
Man-Made Synthetic Fibers - Polyester
Man-Made Synthetic Fibers - Acrylic and Modacrylic
Man-Made Synthetic Fibers - Olefins
Man-Made Synthetic Fibers - Elastomers
Man-Made Synthetic Fibers - Mineral Fibers
Man Made Fibers - Other Textile Fibers
Fiber Blends
From Fiber to Yarn: Overview - Part I
From Fiber to Yarn: Overview - Part II
Melt-Spun Fibers
Characteristics of Filament Yarn
Yarn Classification
Direct Spun Yarns
Textured Filament Yarns
Fabric Construction - Felt
Fabric Construction - Nonwoven fabrics
A Fashion Data Base
Fabric Construction - Leather
Fabric Construction - Films
Glossary of Colors, Dyes, Inks, Pigments and Resins
Fabric Construction – Foams and Poromeric Material
Knitting
Hosiery
Glossary of Fabrics, Fibers, Finishes, Garments and Yarns
Weaving and the Loom
Similarities and Differences in Woven Fabrics
The Three Basic Weaves - Plain Weave (Part I)
The Three Basic Weaves - Plain Weave (Part II)
The Three Basic Weaves - Twill Weave
The Three Basic Weaves - Satin Weave
Figured Weaves - Leno Weave
Figured Weaves – Piqué Weave
Figured Fabrics
Glossary of Art, Artists, Art Motifs and Art Movements
Crêpe Fabrics
Crêpe Effect Fabrics
Pile Fabrics - General
Woven Pile Fabrics
Chenille Yarn and Tufted Pile Fabrics
Knit-Pile Fabrics
Flocked Pile Fabrics and Other Pile Construction Processes
Glossary of Paper, Photography, Printing, Prints and Publication Terms
Napped Fabrics – Part I
Napped Fabrics – Part II
Double Cloth
Multicomponent Fabrics
Knit-Sew or Stitch Through Fabrics
Finishes - Overview
Finishes - Initial Fabric Cleaning
Mechanical Finishes - Part I
Mechanical Finishes - Part II
Additive Finishes
Chemical Finishes - Bleaching
Glossary of Scientific Terms
Chemical Finishes - Acid Finishes
Finishes: Mercerization
Finishes: Waterproof and Water-Repellent Fabrics
Finishes: Flame-Proofed Fabrics
Finishes to Prevent Attack by Insects and Micro-Organisms
Other Finishes
Shrinkage - Part I
Shrinkage - Part II
Progressive Shrinkage and Methods of Control
Durable Press and Wash-and-Wear Finishes - Part I
Durable Press and Wash-and-Wear Finishes - Part II
Durable Press and Wash-and-Wear Finishes - Part III
Durable Press and Wash-and-Wear Finishes - Part IV
Durable Press and Wash-and-Wear Finishes - Part V
The General Theory of Dyeing – Part I
The General Theory Of Dyeing - Part II
Natural Dyes
Natural Dyes - Indigo
Mordant Dyes
Premetallized Dyes
Azoic Dyes
Basic Dyes
Acid Dyes
Disperse Dyes
Direct Dyes
Reactive Dyes
Sulfur Dyes
Blends – Fibers and Direct Dyeing
The General Theory of Printing
There are currently eight data bases on this blogspot, namely, the Glossary of Cultural and Architectural Terms, Timelines of Fabrics, Dyes and Other Stuff, A Fashion Data Base, the Glossary of Colors, Dyes, Inks, Pigments and Resins, the Glossary of Fabrics, Fibers, Finishes, Garments and Yarns, Glossary of Art, Artists, Art Motifs and Art Movements, Glossary of Paper, Photography, Printing, Prints and Publication Terms and the Glossary of Scientific Terms, which has been updated to Version 3.5. All data bases will be updated from time-to-time in the future.
If you find any post on this blog site useful, you can save it or copy and paste it into your own "Word" document etc. for your future reference. For example, Safari allows you to save a post (e.g. click on "File", click on "Print" and release, click on "PDF" and then click on "Save As" and release - and a PDF should appear where you have stored it). Safari also allows you to mail a post to a friend (click on "File", and then point cursor to "Mail Contents On This Page" and release). Either way, this or other posts on this site may be a useful Art Resource for you.
The Art Resource series will be the first post in each calendar month. Remember - these Art Resource posts span information that will be useful for a home hobbyist to that required by a final year University Fine-Art student and so undoubtedly, some parts of any Art Resource post may appear far too technical for your needs (skip over those mind boggling parts) and in other parts, it may be too simplistic with respect to your level of knowledge (ditto the skip). The trade-off between these two extremes will mean that Art Resource posts will hopefully be useful in parts to most, but unfortunately may not be satisfying to all!
Introduction
In order to understand the coloring of textile materials, you need to have some understanding of the general theory of dyeing and printing. After reading this post, and if you are still unsure of definitions, terminologies or properties used of fabrics that this post assumes you should know but you don't, then consult the "Preamble" above and click on any art resource post or glossary that might provide that missing information for you.
This post will concentrate on the general theory of dyeing.
O,H & S Issues with Dyeing Fabrics and Textiles
In general, always get a Material Safety Data Sheet (MSDS) from the manufacturer on all dyes and auxiliary compounds you wish to use for any art/craft project. If you do not possess the MSDS you need, go to the retailer who you have purchased the product from and they should provide you with the MSDS. If they cannot, for some unknown reason, then go to Chemists (Commonwealth Countries) or a Drug Store (USA) and ask them for assistance. Usually they are friendly enough to give some advice or point you to where you might obtain the necessary information.
In general, always wear rubber gloves to prevent dyes from being absorbed through the skin. Protective clothing - smock or plastic apron - is also recommended to prevent damage to your clothes. Wear old or disposable shoes and ventilate your work area with a fan to dissipate or exhaust fumes. Remember, not all natural dyes are harmless and/or not all man-made dyes are toxic. Wearing face masks and eye googles might be a pain, but not wearing them when you should, might one day render you in far greater pain! There is only one you, and needless to say, you are special!
It goes without saying that any utensils used in the dyeing process should never be used for food preparation or for any other purpose, even if you have convinced yourself that the cleaning procedures you have employed were excellent.
I cannot keep stressing that all work should be performed in well ventilated areas that are not "common" areas shared by children and other adults, who are not directly involved in your project. Avoid inhalation of dyes and consult my previous posts, namely, Units Used in Dyeing and Printing of Fabrics and Occupational, Health & Safety.
An indigo dyer, using a natural dye in India. Poor legislative and regulatory oversight creates dyed skin for the untouchable caste dyers in India. Even natural dyes are harmful and are thoughtlessly used in countries that have not put in place or monitored the necessary legislative and regulative oversight to demand safety first procedures.
If by any chance, something went amiss and you have inhaled dyes or irritated your eyes or any part of your body because of them, seek medical advice as quickly as possible. Better to be safe then unsure!
Introduction to Dyeing
Dye baths of Cliff Rose, Wild Carrot, Navajo Tea, Ground Lichen and Rabbit Brush.
Dye molecules are organic compounds, which are responsible for the coloring of textile materials. The optical properties of textile materials depends on the incident light that are absorbed, reflected and/or transmitted. The color of textile materials is dependent on the light waves that are reflected and absorbed.
Generally, dyeing is the process of coloring textile materials by immersing them in an aqueous solution called dye liquor. The dye liquor normally contains the dye, water and auxiliary compounds. To improve the effectiveness and efficiency of dyeing, heat is usually applied to the dye liquor. The theory of aqueous dyeing (as explained below) needs modification if an organic solvent is involved instead of water.
The general theory of dyeing focuses on:
(a) Forces of repulsion, which are developed between the dye molecules and water.
(b) Forces of attraction, which are developed between the dye molecules and the fibers.
Dye molecules may be classified from two different approaches:
(a) According to the chemical constitution of the dye molecule itself.
(b) According to the method of application.
In this series, to make the chemistry as manageable as possible, we shall generally concentrate on classifying dyes according to the method of application. However, before we do it is instructive to define some basic chemical terminology. Hold your breath and read on!
Anions are negatively charged species, whereas cations are positively charged species. Hence, dye molecules generally are organic compounds (i.e. mainly composed from carbon, hydrogen, oxygen, nitrogen and sulfur) and so may be classified as:
(a) anionic – in which the color is caused by the negative part of the dye molecule.
(b) cationic – in which the color is caused by the positive part of the dye molecule.
(c) disperse – in which the color is caused by the whole molecule since it is non-polar (no negative or positive parts within it).
Dyes used for mass dyeing of t-shirts in India.
The Fiber
Textile fibers are also generally organic compounds and develop a slight negative charge on the surface of the fiber, when immersed in an aqueous solution. Since the dye molecule in an aqueous solution is also slightly negative, they will repel one another (i.e two likes repel) and so conditions within the dye liquor have to be developed in order to overcome this tendency for repulsion, thereby promoting the entry of the dye molecules into the polymer system of the fiber.
Just as a reminder, a simplified and exaggerated representation of a fiber’s polymer system is given below. Each polymer system tends to possess several amorphous (chaotic) and crystalline (structured) regions. This assists in the cohesion of the polymer system. Whenever several individual polymer units are aligned or orientated in more or less parallel order, they form the crystalline regions, which only have extremely small voids between them and so generally prevent dyes or water molecules entry into the crystalline regions. Amorphous regions occur whenever polymer units are not orientated or are completely disorganized in a random fashion. It is these regions that often are the entry points for dye and water molecules into the fabric. Generally, the most important forces of attraction between the polymer units are hydrogen bonds and van der Waals forces.
A schematic of the regions of a fiber polymer system.
Note: These regions of the fiber polymer system will be often referred to in the following posts on this blogapot on dyeing and printing of textile materials and so you should grab this image and place it on your desktop.
The Role of Water
Water in aqueous dyeing is critical since it must dissolve or disperse the dye and moreover, it acts as the medium through which the dyed molecules are transferred into the fiber.
Water is polar (i.e. possesses relatively negative and positive parts to it) and so any polar group in the dye molecule is attracted to water molecules and this is the reason why dyes that are polar dissolve in it. In the case of disperse dyes, which does not have negative or positive parts to it, and so are hydrophobic (water hating), they purposely disperse within the water (e.g. may be assisted by dispersing agents) rather than dissolving in it. Think of it as dye droplets suspended by the water molecules that move randomly to keep these dye droplets afloat and so prevent the dye droplets from accumulating at the bottom of the container.
Generally, if a dye molecule dissolves in water, the act of dissolution is undesirable to ensure effective and an efficient transfer of the dye into the fiber, unless this attraction can be negated. Nevertheless, in some instances the rate of dye uptake from the water to the fiber needs to be controlled in order to ensure a uniform coloration of the fiber.
To encourage the dissolved dye to leave the water and enter into the fiber, heat is usually required. This also ensures an adequate penetration of dye into the polymer system of the fiber. Heating the dye liquor promotes the dissociation of water into its polar parts and so the dye liquor becomes more ionic, which promotes the repulsion between water and dye molecules and so promotes dye uptake by the fiber polymer system.
Water, assisted by heat, also swells fibers that are hydrophilic (water loving) and in doing so enlarges the surface and internal voids of the fabric, which makes the fiber polymer system far more accessible to large dye molecules, that otherwise at room temperature would be confronted with small entry voids in the fiber and so the small entry points would prevent the dye molecule from diffusing into the fiber.
The Role of Electrolytes
Electrolytes (such as salts like sodium chloride) are ionic compounds that readily dissolve in aqueous systems as cations (e.g. Na+ is the cation of sodium chloride) and anions (e.g. Cl- is the anion of sodium chloride).
The addition of heat and an electrolyte to the dye liquor of an ionic dye increases the uptake of the dye by the fiber because of the following reasons:
(a) Heat promotes to charge ions in solution and so assists in the water-dye repulsion, thereby assisting in the dye-fiber attraction.
(b) Electrolytes dissociate into ions in water and so assist the dye liquor-dye molecule repulsion, thereby assisting the dye molecule-fiber attractions.
(c) The electrolyte ions neutralize any fiber surface charge and so assist the dye molecule - fiber attraction.
(d) Heat also enlarges the surface and internal voids of the fiber thereby, increasing and deepening the passage of large dyed molecules into the fiber.
The Role of Heating the Dye Liquor
Rather than repeat (a) and (d) above, we shall add that heating the dye liquor also imparts a greater translation energy to the dyed molecules and so reduces the time of dye uptake of a particular fiber, with all other factors being equal. It also enables a greater penetration of the dye into the fiber polymer system (i.e. dye molecules entering the amorphous regions of the fiber do so and at a greater depth).
When the dyed liquor cools and the fibers dry, the surface and internal voids of the polymer system will return to their original size, trapping and entangling the dye molecules that are now resident within it. In this environment, weak van Waals forces of attraction between the dyed molecules and the polymer system of the fiber assist to retain the dye molecules within the fiber's polymer system.
High Temperature Dyeing
Dyeing at temperatures from 100oC to 130oC under pressure of 170kPa (note: one atmosphere is 101.3 kPa) is termed high temperature dyeing. Hydrophobic fibers, such as polyester fibers, are commercially dyed in this way using dye liquors (as distinct from sublimation dyeing) because under normal atmospheric conditions, their extremely crystalline polymer system will not allow a good dye uptake.
When dyeing at high temperature, dye molecule penetration of the fiber polymer system is increased significantly. At temperatures above 100oC and under pressure, the heat generates a very large amount of energy in the constituents of the dye liquor. This swells the fiber, and so enlarges its surface and internal voids, enabling the dye molecules to penetrate into the fiber system more readily and deeper.
Dye Auxiliary Compounds
Dye auxiliary compounds assist the dyeing process and include: carriers or swelling agents, leveling agents, anti-foaming agents, dispersing agents, detergents and wetting agents. The way these auxiliary agents affect the dyeing process is chemically complex and so beyond this series. Nevertheless, their purpose and use will be explained below.
Carriers or Swelling Agents
The purpose of carriers added to the dye liquor is to improve the dye exhaustion for highly crystallized fibers such as polyesters. Due to their very crystalline nature, usually only pale colors can be achieved by aqueous dyeing without carriers (unlike sublimation dyeing). These carriers tend to swell the fiber, and so enlarge the size of the surface and internal voids of the fiber polymer system, thereby enabling greater dye uptake and penetration. In general, carriers are only used to dye polyester fibers in aqueous liquor baths with disperse dyes.
Disperse dye carrier: NSC.
Leveling Agents
The purpose of adding a leveling agent to the dye liquor is to produce a more uniform color in the textile materials. Leveling agents tend to slow down the dye uptake of the fabric and so they are also known as retarding agents or retarders. The use of retarders is essential in cases where dyes rush into the fiber and so produce uneven colored textile materials.
Leveling agents are surface-active agents and are chemically related to soaps, synthetic detergents and wetting agents. They may be anionic, cationic or non-ionic organic compounds.
High-temperature leveling agent, M214DD.
Anionic Leveling Agents
These molecules consist of large negatively charged or anionic organic radicals, with the corresponding cation usually a sodium cation, that assists the water solubility of the leveling agent.
These anionic leveling agent radicals are attracted to cationic or positive sites on the fiber. As the dye bath is heated, a two-fold process occurs:
(a) The anionic leveling agents are slowly removed from the positive sites of the fiber, due to the disruptive Brownian motion of the water molecules, which is greater the higher the temperature of the dye bath.
(b) The anionic dye molecules obtain sufficient energy to overcome the repulsive forces between the anionic dye molecules and the anionic nature of the retarder and moreover, its attraction to the positive sites on the fiber is stronger than any disruptive force due to Brownian motion.
Both these processes ensure a more uniform absorption of the dye by the polymer system of the fiber due to the slowing down of dye uptake by the fiber.
Cationic Leveling Agents
The molecules of these leveling agents consist of a large positively charged, or cationic organic radical, with an anionic radical, usually the chloride or bromide anion, which helps to assist the agent's water solubility.
Before dissolution in water both the cationic and anionic parts of the leveling agent are attached. However, on dissolution they are separated and the anionic dye portion has a greater attraction to the cationic part of the leveling agent in the dye liquor, thereby reducing the anionic dye radical substantivity for the fibers. The energy provided by heating the dye bath assists to dissociate very slowly the cationic radical of the leveling agent from the anionic dye radical. The slow release from the cationic leveling radical is why they are known as retardants. Moreover, the slow release of the dye anion ensures a more uniform absorption of the dye by the polymer system of the fiber.
Scouring after Dyeing
Dyeing always leaves some dye molecules on the surface of the dyed textile or cloth. It is essential that these dyed molecules be removed when dyeing is completed. If the dyes are not removed they may result in two problems, namely:
(a) Poor rub-fastness, which may result in the dye rubbing onto adjacent materials.
(b) Poor wash-fastness, which may result in other fabrics being colored by the excess dye resident on the fabric during the laundering process.
Block and roller printed Barege, Grenadine and Merino fabrics employing dyes in a variety of Paisley floral patterns.
Compiled by J. Claude Freres and Co, Paris, France, 1856.
Presented to the National Gallery of Victoria by the Australian Wool Corporation in 1982.
References:
[1] A Fritz and J. Cant, Consumer Textiles, Oxford University Press, Melbourne (1986).
[2] E.P.G. Gohl and L.D. Vilensky, Textile Science, Longman Cheshire, Melbourne (1989).
A cap maker from Kano (Northern Nigeria).
A young tailor sewing finely woven Ewe cloth (Ghana).
Nigerian women wearing a variety of body wraps, some hand-printed and others machine printed.
An Ashanti weaver weaving strips for kente cloth.
Spindles of hand spun cotton (Mali).
Wodaabe woman's embroidered cotton blouse (Niger).
Glazed, indigo dyed Tuareg veil from Kano (Nigeria).
Tuareg mat of leather-bound reeds (Mauritania).
Tuareg leather grain bag with painted lucky designs.
Masquerade costume of grass-netting (Cross River, Nigeria).
Tuareg embroidered panel (Central Sahara).
Tuareg painted leather cushion (Mali).
Strip-weave (Burkina-Faso).
Painted Senufo strip woven cotton cloth (Ivory Coast).
Picking indigo leaves for dyeing (Oshogbo, Nigeria).
Skeins of wild silk for sale in Kano market (Nigeria).
Spindles of handspun cotton and indigo dyed veils wrapped ready for sale in Kano market (Nigeria).
A Hausa shopkeeper selling synthetic indigo balls (Keno, Nigeria).
A Hausa trader selling indigo-dyed veils (Kano market).
A Nigerian village trader selling handwoven cloth.
