Saturday, December 19, 2020

The Marketing of Art
Art Essay

Marie-Therese Wisniowski


Season's Greetings
No matter what your religion or what your belief system, I hope you have a very enjoyable festive season!
Marie-Therese.

Xmas Mona.


Introduction
The talk below is based on a talk I gave to a meeting of a number of gallery directors in Melbourne several years ago. This will be the last post for 2020. The next post will be on the 9th of January, 2021.

The Marketing of Art
The midnight opening of George Lucas’, “Star Wars: Episode II - Attack of the Clones”, highlighted the marketing strategy of a modern “block-buster” film.



On the weekend of the opening, approximately 10% of the total budget was spent on marketing the film world-wide to whet the appetite of the viewing public [1].



This marketing strategy further substantiated the careful development of a cult following (over a nine film duration) in order to ensure audience performance and participation. At the midnight showing in Sydney (Australia) there were a least four “Yodas”, one Queen, a few princesses, some Jedi knights, a number of clone-troopers, Droids and even a creature dressed as a knife wielding extra-terrestrial butcher. In other words, like science fiction movies and television shows before and after it, “Stars Wars” has become a “living” memory and a “reality” performance art or an "event happening" for a devoted few. It has and will continue to make money over a much longer duration when compared to a number of other “block-busters” that have now faded from our memories. The merchandizing of the clothes, figures, posters, novels, soundtrack and other implements (such as swords) will ensure an on-going sale for a long time to come [2].

Deluxe Clone Helmet.

Art “block-busters” in Australia have emanated from the National Gallery of Australia, where “exclusive” exhibitions have been the cornerstone of a marketing strategy. While media saturation was effective (because of the use of the corporate dollar) in such exhibitions as - “Rodin: A Magnificent Obssession”, “Frida Kahlo, Diego Rivera and Mexican Modernism”, “Monet and Japan” and “Chihuly: Masterworks in Glass” - there was no emphasise on involving the public other than in a passive viewing role [3].



Surprisingly, there was very little merchandizing at these “block-buster” art exhibitions. For example, no prints were available of many of the artworks. In fact, for the Chihuly exhibition, there was not even a sufficient number of exhibition catalogues, post cards or books on this or on any of his artwork available in the Gallery bookshop [4] during the exhibition.





On a local level, the “Parisian Posters” exhibition, was initiated through a unique partnership program between the National Gallery of Australia and the Newcastle Region Art Gallery. From a collection of 900 lithographs printed at the prestigious Mourlot Studio in Paris, fifty-five lithographs by Picasso, Matisse and Chagall were selected for exhibition. These posters that have rarely been seen, were lithographic posters of the great masters, which revealed the brilliant collaboration between artists and printmakers [5].

In this instance, there was also no merchandizing product available. In other words, the lack of merchandizing prohibited the viewer from “living and breathing” the artwork and so the exhibition experience became transitory for most. Clearly, a “block-buster” in the art world is not allowed to be associated with the marketing hype of the film world (even though both are intrinsically passive media forms). It is no wonder that on a weekly basis more people will view “poor” films rather than engage with “excellent” art.

A comparison study of attendance figures highlights the role strategic marketing plays. In the United States market, “Attack of the Clones”, played in 3,161 theatres on opening night, attracting approximately nine million patrons [6]. The “Cezanne Exhibition” at the Philadelphia Museum of Art attracted a record breaking 548,741 visitors over a fourteen week run [7]. The National Gallery of Australia attracted 589,569 visitors overall in the 2000/01 financial year in this market [8]. In other words, film resonates with the public much more than art does.

The most elementary basis of marketing is the process of exchange[9]. Simply put, person A has a product that person B wants and an exchange is agreed upon in terms of a particular medium (i.e. pigs, cows, people or even money). Art marketing intervenes in that process by providing a number of auxiliary “assists” in the terms of configuration, symbolization, facilitation and evaluation [10]. It is the oil, which lubricates the process of exchange.



How artworks reach their particular markets have interesting cultural and historical routes. In some cultures, it is via spiritual leaders, whereas in the Western culture (which has become more secular) it has been largely shaped by the form of the ubiquitous art dealer, who acts as both a general agent for a stable of artists as well as a local retailer [11]. However, after the second world war, a number of different distribution channels started to emerge. For example, widely distributed art galleries, internet art selling sites, auction houses, workshops, subscription organizations, publishers, wholesalers, direct artist-collector sales and art cooperatives provided a somewhat chaotic, uncoordinated variety of distribution outlets [12].



While no major retailer is merchandizing artworks, mass media distribution channels suddenly appear. For example, in the World Series Cricket between Australia and South Africa (an international sport), a national TV network was merchandizing Pro Hart’s fine-art print - “Bush Cricket” - more as a symbolic celebration of the game rather as an artwork in its own right [13].

Pro Hart’s fine-art print – Bush Cricket.

Promotion is the “engine” of the marketing program and involves publicity, advertising, sales promotion and direct marketing.



Planned promotional activity over a period of time - weeks, months or even years - is called a campaign. All campaigns no matter how they are executed and regardless of their goals, need an effective strategy and plan.



The campaign strategy should be part of the bigger picture developed through the divisions of vision, mission, goals, business plan and marketing strategy. Developing a campaign strategy is equivalent to a dance routine - it makes you go through all the steps. It takes you through the P’s of marketing: the public; the product; the price; the promotion and the place - thereby providing a structure for analyzing the product, the external environment and the outcomes [14].



The public or rather the market is usually couched in terms of market segmentation and the target market [15]. Market segmentation and target market center on recognizing that the total market may need to be divided into smaller and more homogeneous cohorts, that may better resonate with the product being marketed [16]. For example, Pro Hart’s “Bush Cricket” was targeted toward a sporting audience rather than to an educated art audience. Note: Sporting audiences view framed signed team outfits, which they hang on their wall, as legtimate art and so sporting memobrilla effectively competes for the art dollar.



The product - as in the five Ps - can be thought of in the following terms: its formal characteristics (i.e. its physical appearance and requirements); its core benefits (i.e. its exclusivity, status and individuality) and its augmented benefits (e.g. framed or unframed etc) [17]. In the case of “Bush Cricket” the printed edition was limited to 500 and the marketing strategy aimed at exclusivity and status (i.e. “It's a Pro Hart; it's a limited edition artwork!”)



It is clear that pricing decisions are the major plank in the marketing of a product. “Bush Cricket” was priced at AUD$613 (at the time of selling) and moreover, market research deemed that a sporting audience was prepared to pay this price for a piece of art produced by “the common man’s artist”.



Promotion is the communication dimension of marketing: potential customers are identified, informed and persuaded to buy the product on offer[19]. What form the promotion takes is clearly dependent on other elements of the marketing strategy, such as, the size of the target market, the exclusivity of the product and of course, the price. For example, it is unwise with respect to expenditure in promoting any product to be structurally greater than the maximum income realization from a potential market.



The last element in any marketing strategy is “the place”. That is, the distribution channel for the product. Should the product be sold directly to the customer via studio sales, galleries, fairs and shows, commission, community markets, websites or some other retail outlet [20].



Major marketing events such as “block-buster” art exhibitions and art festivals do not as yet involve audience performance and participation in the same “cult” mode that has been established by carefully managed “block-buster” movies. For example, with respect to the latter, part of the strategy involved George Lucas being choosy about locations, insisting on top-of-the-line cinemas with digital sound. Paul Dergarabedian, president of exhibitor relations said, “No apologies need to be made for an opening this big. This is the fifth installment of “Star Wars” and for this film to do so well these many years later and still be relevant, it’s a testament to the power of Lucas’ vision and the allure it has for audiences” [21].

Clearly, these strategies are not intended to be the linchpin of the creative process, but rather must be designed to underpin the financial platform on which artists can continue to engage in the creative process. In other words, marketing is a means to bring the art to the public. It is not an end in itself. Art is the end goal. Afterall, when we view a “Matisse”, we feel his spirit, and so his art.



Marketing in itself does not have that spirit. It may deliver this spirit to others - that was what George Lucas did when he made us want to rust onto a simple ideal - “Good triumphs Evil”. Marketing has nothing to do with the corrupting of art - it has everything to do with the delivery of art. Without such delivery, art will become a past-time activity of the “few” to be engaged by a small select group in our society. Marketing of art is a means to bring to the multitude the act of engaging with art. It is nothing more than a simple tool to facilitate engagement. After all, we as artists have produced our visions - it is the role of not only ourselves but for others to make it known and to make it accessible in order to be owned and/or shared by others. Starving artists are many, but none of us really want to be in that category - no matter how noble we pretend it is!


References:
[1] “Star Wars - Episode II - Attack of the Clones” 2002.
[2] Prequel Multimedia Gallery: Fan Scenes, 2002.
[3] National Gallery of Australia, 2002.
[4] National Gallery of Australia, “1999 - 2000 Annual Report”, p20.
[5] Newcastle Region Art Gallery, “Parisian Posters: Picasso, Matisse, Chagall”
Exhibition Information Flyer, 2002.
[6] Yahoo ! Movies: Weekend Box Office Report, 2002.
[7] Philadelphia Museum of Art, Press Release, 2002.
[8] National Gallery of Australia, “2000 - 2001 Annual Report”. Appendix 7, p136.
[9] Mokwa M.P., Nakamoto, K. and Enis B.E.in, “Marketing the Arts”,
Eds Mokwa M.P., Dawson, W.M. and Prieve, E.A. Praeger Publishing, New York, 1980, p16.
[10] ibid. p16.
[11] Goodman C.J., “Art Marketing Handbook”, gee tee bee, New York, 1978, p4.
[12] ibid. p10.
[13] Channel Nine Wide World of Sport, Baggy Green, Home of Australian Cricket, 2002.
[14] Australia Council, Marketing Strategies for Arts Organisations, 2002.
[15] Stokes, J. “Earning a Living in the Visual Arts and Crafts”, Southward Press, Sydney, 1997, Ch12.
[16] ibid. Ch12.
[17] ibid. Ch12.
[18] ibid. Ch12.
[19] ibid. Ch12.
[20] ibid. Ch12.
[21] Yahoo ! Movies: Weekend Box Office Report, 2002.

Saturday, December 12, 2020

Tsutsugaki - Freehand Paste-Resist Dyeing
Art Essay

Marie-Therese Wisniowski


Preamble
For your convenience I have listed other posts on Japanese textiles on this blogspot:
Discharge Thundercloud
The Basic Kimono Pattern
The Kimono and Japanese Textile Designs
Traditional Japanese Arabesque Patterns (Part I)
Textile Dyeing Patterns of Japan
Traditional Japanese Arabesque Patterns (Part II)
Sarasa Arabesque Patterns (Part III)
Contemporary Japanese Textile Creations
Shibori (Tie-Dying)
History of the Kimono
A Textile Tour of Japan - Part I
A Textile Tour of Japan - Part II
The History of the Obi
Japanese Embroidery (Shishu)
Japanese Dyed Textiles
Aizome (Japanese Indigo Dyeing)
Stencil-Dyed Indigo Arabesque Patterns (Part V)
Japanese Paintings on Silk
Tsutsugaki - Freehand Paste-Resist Dyeing
Street Play in Tokyo
Birds and Flowers in Japanese Textile Designs
Japanese Colors and Inks on Paper From the Idemitsu Collection
Yuzen: Multicolored Past-Resist Dyeing - Part 1
Yuzen: Multi-colored Paste-Resist Dyeing - Part II


Tsutsugaki - Freehand Paste-Resist Dyeing[1]
This freely drawn design technique has a spontaneity not found in other textile design fields. Its bold, unique motifs, outlined in white, contrast with the deep indigo blue, and its bright colors are beautifully rendered on cotton. Unlike the repeated designs of stencil dyeing, large, freehand motifs dominate the overall design of tsutsugaki textiles.

A tsutsugaki wrapping cloth with auspicious motifs of pine, plum, and tortoise, with family crest.

Commoners have used tsutsugaki to decorate clothing, furoshiki, bedding, banners, and even children's towels since the Edo period. It was customary then for a bride to be given a trousseau by her family when she married, consisting of all the clothing and household textile items she would need during her married life. As commoners did not have access to expensive silks, these resourceful people used cotton to create beautifully designed utilitarian items. With indigo dye and paste resist, they had their family crests and symbols of good luck, such as the phoenix, lion, crane, turtle, pine trees and paulownia, dyed onto the trousseau items. The specialists who created these masterpieces worked long and hard to attain textiles of strength, beauty and durability.
Courtesy reference[1].

A bridal wrapping cloth to wrap and carry the new bedding that is part of her wedding-day trousseau. The patchwork bag with the string is a rice bag.
Courtesy reference[1].

Rice paste is once again the resist used to draw the white lines that delineate these vibrant designs. With a water proof paper cone (called a tsutsu), the paste is drawn onto the fabric, following lines previously laid out with albans. After a coating of liquid soybean extract has been brushed over the material, pigments are applied to the designs. These colored areas are then covered with paste and sprinkled with sawdust to protect them should they come in contact with other pasted areas in the dye vat. Then the fabric is put into the indigo vat.

Applying paste resist with a waterproof paper cone (tsutsu) along a line traced in aobana.
Courtesy reference[1].

When the indigo-dyed fabric first comes out of the vat, it is a light green, but contact with air causes the dye to oxidise, and its color changes to deep blue.

A happi coat with a rabbit motif by the Konjin Workshop.
Courtesy reference[1].

Additional dips in the dye vat are carried out until the desired depth of color is reached. After this dyeing process is finished, the fabric is soaked in water to remove the paste, and the piece is stretched on bamboo shinshi rods to dry. Where the paste lines were, white lines remain, outlining the pictures painted by the artists.

Sash to carry a baby on the back. The family crest can be seen on the fabric.
Courtesy reference[1].

The tsutsugaki technique was born from the use of three plants: cotton, brought from Korea; rice, Japan's staple food; and indigo, which was grown throughout the country. TsuTsugaki flourished over two hundred and sixty years of the Edo period. Fortunately, the recent movement to revive the Japanese folk craft is helping a number of artist-craftsmen to continue to create tsutsugaki textiles according to traditional techniques.

A tsutsugaki shop curtain (noren) by Konjin Kobo Tsutsugaki Workshop.
Courtesy reference[1].

A wrapping cloth decorated with a Chinese lion and peony (karajishi botan) motif by Konjin Workshop.
Courtesy reference[1].


Reference:
[1] S. Yang and R. ZM. Narasin, Textile Art of Japan, Tokyo (1989).

Saturday, December 5, 2020

Acid Dyes[1-2]
Art Resource

Marie-Therese Wisniowski

Preamble
This is the one hundredth and sixth 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 РPiqu̩ 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
Dyes may be classified according to:
(i) The chemical constitution of the dye molecules or;
(ii) According to the method of application.

We shall use the second approach and classify the dyes according to their method of application. Today, we shall concentrate on acid dyes.

Acid dyes are so called because they are usually applied under acidic conditions. Acid dyes are negative charge carriers. The fibers mostly colored by acid dyes are man-made synthetic, nylon fibers and the natural protein fibers such as wool, silk, mohair etc. Acidic dyes generally have less affinity for cellulosic fibers, when compared to say, direct dyes. They have no affinity for cellulosic fibers such as cotton, linen or jute or on any fibers that are sensitive to weak acids. These dyes vary in fastness with respect to washing, laundering, dry cleaning and perspiration.

Merino Wool Dyed With Jacquard Acid Dyes.

Acid dyes are normally sodium salts of sulfonic acid - hence, their name. That is, the generalized formula for an acid dye molecule is DNa+ SO3-, where D is the color radical or component of the acid dye molecule.

The application of acid dyes to protein fibers such as wool and silk results in an ionic or salt link between the dye molecule and the fiber polymer. In the case of wool polymer, it is firstly acidified (addition of H+) in the dye bath.

Step One: The amino (NH2) group of the wool polymer is acidified.
Note: H+ is attached to the amino group of the wool polymer system.
Courtesy of reference [1].

This can be more broadly shown in terms that the wool polymer system now has positive charges on the surface of the fiber polymer system.

The acid solution places positive charges on the surface of the wool fibers.
Courtesy of reference [2].

Once acidified, the positively charged amino group in the wool polymer system is then attracted to the negative radical of the dye molecule.

Step Two: The positive charged amino group of the wool polymer forms an ionic link to the dye anion.
Note: The Na+ cation has a greater affinity for water and so goes into solution and is not involved in the dye attachment to the wool polymer system. Since it has the same charge of the fiber, it avoids it.
Courtesy of reference [1].

This can be shown more holistically as the negatively charged dye molecule being attracted to the positively charged fiber.

Addition of the anionic dye radical.
Note: this shows that the acidic dyes can only be applied to fibers, whose polymer systems have sites that will accept a positive charge from the acidic solution.
Courtesy reference [2].

The anionic (negative) dye molecule forms an ionic link with the cationic (positive) fiber sites.
Courtesy reference [2].

In addition to ionic bonds (see above diagrams) when protein and polyamide fibers are dyed with acid dyes, hydrogen bonds and van der Waals forces of attraction (not shown above) will also be formed between the acid dye molecules and chemical groups of the fiber polymer system.

Some of the acid dyes have a relatively high substantivity to protein fibers and so the fibers may be dyed unevenly. To overcome this, a retarder needs to be added to the dye liquor, such as sodium sulfate called Glauber salt (Na2SO4). The sulfate anion (SO42-) of the salt is much smaller than the dye anion and so it can move in the dye liquor much more rapidly to the positive sites on the fiber and so effectively compete with the dye anions for attachment to these sites. The dye anions have a greater affinity for the positive sites on the fiber, than the sulfate anions and so the sulphate anions retard the rate at which the dye anions can occupy the positive sites of the fiber. This produces a more uniform dyeing of the fiber. The application of heat assists the dyeing process by increasing the kinetic energy or speed of the dye anions as they move towards the positive sites on the fiber, therefore effectively overcoming the retarding effect of the sulfate anions. Moreover, the bulky, speedier dye anions can knock off the smaller attached SO42- molecules on the fiber sites and so over a longer duration in time, the addition of salt ensures that the dye gives a much more extensive and even coverage over the fabric.


Printing with Acid Dyes
Once an acid dye printing paste has been applied to the textile material, steaming the printed pattern is necessary, since the steam heated water molecules enable the dye molecules of the printing paste to transfer from the fiber surface into the fiber polymer system. It does so, by enlarging the voids in the amorphous regions of the fiber polymer system, and so enabling a greater dye penetration into the fabric. Note: On cooling, the fiber voids are shrunk in size, thereby trapping and entangling the acid dyes and so promoting not only ionic bonding, but hydrogen bonding and van der Waals forces of attraction, all of which fix the dye molecule to the fiber polymers.

The process of printing is different to dyeing, since it requires a lower liquor ratio and a thickener to ensure that the acid dye will not run when applied to the textile material.


Properties of Acid Dyes
Light Fastness
Dyed and printed acid colors have “good” light fastness, with a rating of about 4-5. The electronic stability of the chromophores of acid dyes is such that they can resist the degrading effects of UV sunlight for a considerable duration.

Wash Fastness
The wash fastness of acid dyed textile materials is rated about 2-3 for acid dyes with good leveling characteristics, 3-4 for those with average leveling characteristics, and 4-5 for those with poor leveling characteristics.

Two factors influence the wash fastness of acid dyed textile materials and these are:
(i) Acid dyed molecules, which are loosely held or which have not penetrated the fiber polymer system of wool or nylon sufficiently may be removed on laundering, due to the ionic and hydrogen bonds that cohere it to the fiber polymer system being severed via hydrolysis.
(ii) Acid dyes are acidic and so resistant to acids, but being acids will combine with alkalis (which are bases) such as the detergents used in washing apparel and so the acid-base combination will sever the cohesive bonds and assist in the dye removal from the fiber.

Leveling Characteristics
Acid dyes are divided into three groups according to their leveling characteristics namely:
(i) Acid dyes with good leveling characteristics (Acid Blue 45, 63010).
The relatively poor substantivity of this acid dye is responsible for their good leveling characteristics. As the dye molecules have less attraction for the fiber they will migrate only slowly into the wool or nylon polymer systems. However, to obtain sufficient substantivity, and to ensure adequate exhaustion, sulfuric acid is added to the dye liquor to obtain a pH between 3.5-4.5. Their lack of substantivity is evidence by the poor wash fastness. However, their light fastness is very good to excellent.

(ii) Acid dyes with average leveling characteristics (e.g. Acid Blue 83, 42660). Acetic acid is used to acidify the dye liquor to a pH between 5-6. At this pH adequate exhaustion of the dye occurs. Lowering the pH leads to uneven dyeing. The wash fastness of these acid dyes is fair, whilst their light fastness is good to very good.

(iii) Acid dyes with poor leveling characteristics (Acid Yellow 42, 22910).
These dyes are also known as fast acid dyes, acid milling dyes or neutral dyeing acid dyes. They have the best substantivity of all acid dyes, but possess poor leveling characteristics. Unless care is taken during dyeing, their relatively good substantivity for the fiber may result in too rapid a dye uptake and consequently lead to unlevel dyeing.

The excellent substantivity of these dyes is attributed to the sodium sulfonate groups (NaSO3) that are present in their molecular structure. The greater polarity of acid milling dyes is due to these extra groups that imparts to them a higher substantivity, thus requiring a pH between 6-7 in order to obtain slower exhaustion and more level dyeing. Note: pH 7 is neutral; that is, neither an acidic or basic dye liquor.

The wash fastness of these dyes is good to very good whist their light fastness is fair to good. The better wash fastness of these dyes compared to (i) and (ii) is due to the presence of a greater number of sodium sulfonate groups.

Dye Uptake
Heating of the acid dye liquor is essential to ensure satisfactory dye uptake. Below about 40oC, there is practically no transfer of dye molecules from the dye liquor to the fiber polymer system. However, the rate of dyeing increases steadily as the temperature rises. Increasing the temperature of the dye liquor provides the energy required by the dye molecules to leave the dye liquor and enter the fiber polymer system.


References:
[1] E.P.G. Gohl and L.D. Vilensky, Textile Science, Longman Cheshire, Melbourne (1989).
[2] A. Fritz and J. Cant, Consumer Textiles, Oxford University Press, Melbourne (1986).