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India
has been renowned for its printed and dyed cotton cloth since the 12th century
and the creative processes flourished as the fabric received royal patronage.
Different styles of designs have evolved in different parts of the country
and West Bengal is noted for it's bold and vibrant motifs.
The
fabric to be printed is washed free of starch and soft bleached if the
natural gray of the fabric is not desired.
If
dyeing is required as in the case of saris where borders or the body is
tied and dyed it is done before printing.
The
fabric is again washed to remove excess dye and dried thoroughly.
The fabric is stretched
over the printing table and fastened with small pins. This is an important
stage as there should be a uniform tension in the fabric and no ripples.
Color is mixed separately
in another room. Usually pigment dyes are used for cotton. You can read
more about dyes at the end of this page. Color is kept in a
tray on a wheeled wooden trolley with racks which the printer drags along
as he works. On the lower shelves printing blocks are kept ready.
The tray of color
rests on another tray which contains a thick viscous liquid made from
the pigment binder and glue. This gives the color tray a soft base which
helps to spread color evenly on the wooden block. Blocks are made of
seasoned teak wood by trained craftsmen. The underside of the block has
the design hand carved on it by the block maker. Each block has a wooden
handle and two to three cylindrical holes drilled into the block for free
air passage and also to allow release of excess printing paste. The new
blocks are soaked in oil for 10-15 days to soften the grains in the timber.
The printing starts
form left to right. The color is evened out in the tray with a wedge of
wood and the block dipped into the outline color (usually black or a dark
color). When
the block is applied to the fabric, it is slammed hard with the fist on
the back of the handle so that a good impression may register. A point on
the block serves as a guide for the repeat impression, so that the whole
effect is continuous and not disjoined. The outline printer is usually an
expert because he is the one who leads the process. If it is a multiple
color design the second printer dips his block in color again using the
point or guide for a perfect registration to fill in the color. The third
color if required follows likewise. Skill is necessary for good printing
since the colors need to dovetail into the design to make it a composite
whole. The fabric, after
pigment printing is dried out in the sun. This is part of the fixing process.
It is then rolled in wads of newspapers to prevent the dye from adhering
to other layers and steamed in boilers constructed for the purpose. Silks
are also steamed this way after printing. After steaming, the material
is washed thoroughly in large quantities of water and dried in the sun,
after which it is finished by ironing out single layers, which fix the
color permanently.
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A
brief description of Dyes
Pigment dyes
Pigment colors are
mixed with k erosene and a binder. The consistency should be just right,
for if it is too thick it gives a raised effect on the material, which
spoils the design. Small plastic buckets with lids are ideal for storing
the mixed colors 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 / Reactive
dyes
As the name suggests,
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.
Vegetable
/ Natural dyes
Historically of great
importance, these dyes have acquired even greater importance now because
of their eco-friendly nature.
Bagru Black
This is derived by
mixing acidic solution of iron - often rusted nails/horse shoes etc. with
jaggery (country sugar) allowed to rot for about 10-15 days. Many other
natural substances used for producing dyes are pomegranate skins, bark
of mango tree, vinegar, slaked lime etc.
Bagru Red
This dye is achieved
by combining a source material such as alizarin with alum, the results
ranging from pink to deep red. Indigo Blue
The internationally
famous Bagru Blue is obtained from the indigo bush found throughout India.
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