All About Ajrak Process

This (http://www.ajrakhprinting.co.in) is an amazing website giving in amazing details the process of Ajrak Printing. Owned by Ranamal Khatri, the master craftman, this website can be used as an authentic one to study the process.I met Mr. Ranamal Khatri during my visit to Jodhpur. This site will give you a glimpse of the joy of watching Ajrak Made. This gives in details the process, the receipe, the comparison with the earlier process and a mouth-watering view of the products. To top it all, he has put in the process video wherein one can have a look at the process in action. And last but not the least, a look at the artisans working in his workshop and who have made it possible is given. Here are some pictures from the website:

Receipe

Video of the Process

Ajrak Saris

Artisans 

Awards won by Him 

There is a very good M.Des. Research done by B. Sinduja. You can access it here

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Vocabulary of Kantha

Here is a website that gives you the vocabulary of Kantha alongwith the basic stitches.

 

 

Types of Dyes used in Handblock Printing

The following is a brief description of the chemical dyes used in handblock printing in India:

Pigment dyes

Pigment colors are mixed with kerosene and a binder. The mixed color can be stored for a few days. The motif is printed directly on white or light-colored ground with a variety of pigment colors. Pigment colors are widely popular today because the process is simple, the mixed colors can be stored for a period of time, subtle nuances of colors are possible, and new shades evolve with the mixing of two or three colors. Also the colors are visible as one prints and do not change after processing. Colors can be tested before printing by merely applying it onto the fabric. The pigment color is made up of tiny particles, which do not dissolve entirely and hence are deposited on the cloth surface while rapid dyes and indigo sols penetrate the cloth.

Rapid fast Colors

In this process, the ground color and the color in the design are printed on white and/or light-colored grounds in one step. The dyes once mixed for printing have to be used the same day. Standard colors are black, red, orange, brown and mustard. Color variation is somewhat difficult and while printing it is not possible to gauge the quality or depth of color.

Discharge Dyes

These dyes are used if you need to print onto a dark background. Medium to dark grounds are dyed on fabric with specially prepared dyestuff . The printing colors then used on the fabric contain a chemical that interacts with the dye. This interaction simultaneously bleaches the color from the dyed ground and prints the desired color on its place. Areas can also be discharged and left white. The primary advantage of this process is that vivid and bright colors along with white can be printed on top of medium and dark grounds. 

    

Napthol

These are two sets of chemicals which upon reaction produce a third chemical essentially colorful in nature. Fabric is dyed in one and later printed with the other. The chemical reaction produces a third color. However, the biggest drawback of this process is that there are just a few chemicals available which produce colors upon reaction.

Source: http://www.aiacaonline.org/pdf/block-printing-extended-documentation.pdf 

See the images of these prints here : http://www.sashaworld.com/learn/learnframe.htm              

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Why Different types of Reactive Dyes Dye differently

Almost all the reactive dyes are built on a similar structure (Remazol Dye from Hoechst is the exception). This structure consists of (1) a chromophore (the color-bearing group), (2) a reactive group (usually a heterocyclic carbon-nitrogen ring system), and (3) a "leaving group" which is part of the carbon-nitrogen group which is generally a halogen compound (chlorine family).

Influence of Dye characteristics in reactive dyeing:

The major dye variables that affect reactive dyeing are dye chemistry, substantivity,Reactivity and solubility.

Dye chemistry:

Reactive dye has a wide variety in terms of their chemical structure. The two most important component of a reactive dye are the chromophore and the reactive group. The characteristics governed by the chromophore are color gamut, light fastness, chlorine / bleach fastness, solubility, affinity and diffusion.

The dye characteristics governed by reactive group are reactivity, dye-fiber bond stability, and efficiency of reaction with the fiber and affinity. Dyeing conditions, especially the alkali requirements and temperature as well as the use of salt also depends upon the type of reactive group.

Substantivity:

The affinity of dye for a given substrate ( textile material) is called substantivity

Substantivity more depends upon chromophore as compared to reactive system. A high substantivity may results:

• Lower dye solubility.

• High primary exhaustion.

• A high reaction rate.

• Lower diffusion coeffecient.

A low sensitivity of dyes to the variation in the processing conditions such as time, temperature, pH, material to liquor ratio may results:

• Less diffusion.

• Less migration and levelness.

• More difficult to the removal of unfixed dyes.

Substantivity is also the best measure of the ability of a dye to cover dead cotton or immature cotton fibers. Covering power is best when the substantivity is either high or very low. An increase in the dye substantivity may be affected by:

• Lower concentration of dyes.

• Higher concentration of electrolyte.

• Lower temperature.

• Higher pH upto 11.

• Lower liquor to material ratio (M:L)

Reactivity:

High dye reactivity entails a lower dyeing time and lower efficiency of fixation. To improve the efficiency of fixation by reducing dye reactivity requires a longer dyeing time and therefore less effective than an increase in substativity. Also there is wide range of temperature and pH over which the dye can be applied. Altering the pH or temperature, two dyes of intricsically different reactivity may be made to react at a similar rate can modify reactivity of dye.

Solubility:

Dyes of better solubility can diffuse easily and rapidly into the fibers, resulting in better migration and leveling. Increasing the temperature, adding urea and decreasing the use of electrolyte may affect on increase in dye solubility.

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