1.
Report on Natural Dying Process
In NCVI .
November,2011
Submitted to
Nijera Cottage and Village Industries (NCVI)
private limited ,Rajendrapur .Rangpur.
By
Apurba Deb Roy, Consultant, NCVI,
apurba.debroy@gmail.com

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Table of Contents
1. Introduction: ......................................................................................................................................... 3
2. Background: .......................................................................................................................................... 3
3. Scope of work ....................................................................................................................................... 3
4. Review of the exiting dying practices & identification of areas of improvements. ............................. 3
A. Infrastructure: ....................................................................................................................................... 3
B. Management: ........................................................................................................................................ 3
C. Logistics: ................................................................................................................................................ 4
D. Technical: .............................................................................................................................................. 4
4. Hands on training in order to build capacity on natural & fructose dying for the dying group ........... 5
a) Fructose dying: .................................................................................................................................. 5
b) Outputs: ............................................................................................................................................ 5
c) Problems: .......................................................................................................................................... 5
5. Natural Dying & Indigo natural fermentation VAT preparation: ........................................................ 5
a) Dyeing : Natural VAT performance data. ......................................................................................... 7
6. Work on setting an unit for dying maximum length of fabric (10 meters) ........................................... 7
a) Outputs: ............................................................................................................................................ 7
b) Parameters of four color shade (provided by Thomas) .................................................................... 8
c) Oxidizing full length fabric : .............................................................................................................. 8
d. Final out puts: ....................................................................................................................................... 9
e. Problems. .......................................................................................................................................... 9
7. Recommendations: ............................................................................................................................... 9
a) Fructose dying; .................................................................................................................................. 9
b) Natural dying. .................................................................................................................................... 9
c) Full length dying: ............................................................................................................................. 10
8. Overall recommendations. ................................................................................................................ 10

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1. Introduction:
Nijera Cottage and Village industries (NCVI) private limited is an artisan owned social enterprise
worked for producing high quality natural indigo and indigo dyed stuff of different kinds for high end
markets at home and abroad. This is a new initiative on improvements on developing capacity building
for dying workers on natural fermentation VATs on appropriate scale and creating opportunity to dye
full length fabric both natural and fructose dye technique and methods through hands on training .
2. Background:
NCVI is renowned in making indigo dye and dyed stuff for world market since 2008. NCVI has a well
structured house of shibori work and dyeing facilities in the premises including indigo extraction tanks
and other necessary arrangements. Recent marketing collaboration with Harmes and other important
buyers, NCVI is planning to improve the overall dyeing systems in to 100% natural fermentation VATs
performance replacing caustic and hydrose VATs. This is a series of capacity building work of new
technology transfer in order to ensure the supply indigo dyed full length of fabrics and other shibori
products as per demand and order placed by the buyer of international markets.
3. Scope of work
This is an eight (8 days) consultancy work for the following activities;
a) Review the existing dyeing systems and identifies the areas of improvements.
b) Provide hands on training to dying group that can build capacity of dyeing group.
c) Set up a new technology as well as knowledge transfer for indigo natural dye with fructose
d) Work on setting a unit that can dye at least ten meters fabric.
4. Review of the exiting dying practices in NCVI & identification of areas
of improvements.
A. Infrastructure:
1. Lack of water supply in dying section in NCVI is a problem. Natural dying requires huge amount of
water for a) making 600 liters of soft water every week, b) preparing new VATs, c) recharging
existing VATs every week, d) washing of fabric before and after dying.
2. No alternative water source in NCVI except existing hand tube well nearby extraction tank . It is
very difficult to use the existing hand tube well for the above activities when dying activities run
in full swing.
3. The dying room is well ventilated and is appropriate for natural dying process but there is no
ceiling over the VATs . Heat is being generated due to tin roof and directly affects the VATs.
Natural VAT works very well when dying room temperature is below corresponding 0.5 to 1
degree Celsius than outside room temperature.
B. Management:
1. No production Manager for NCVI at present. There is no one who can coordinate the whole
process of natural dying including recording, supervising master dyer and his/her workers,
arranging materials and logistics related to dying activities.

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2. Lack of permanent people in the dying unit interrupted dying follow up process. Present dying
people have no specific job descriptions/task . No daily work schedule for dyer and workers for
the dying unit .Task is being delegated properly, task have been overleaped with one or two
people that effects the dying process and quality .No one is accountable for any sort of
mistakes/unfair means / damages of products.
3. No electrician or mechanics is in NCVI who can help to solve the minor problems such as restore
electrical connections, machineries breakdowns etc.
C. Logistics:
1. There is no oven /gas Chula for boiling the water for dying purposes. An existing small Chula/stove
with wood was difficult to boil water for washing fabrics and other purposes. Cotton fabric needs
hot water with more than 80 degree Celsius and silk fabric needs hot water of 50‐ 60 degree
Celsius .
2. Proper washing of fabric is most important for natural dying process otherwise natural color does
not penetrate in to the yarn because of wax ,tenin and other textile chemical available in fabric
3. Lack of 20‐ 40 capacity stain less utensils/pots for boiling water that was required for washing of
more than 10 meters fabrics.
4. Lack of appropriate liquid soap resulting very poor wash for natural dye.
D. Technical:
1. Indigo dyer and workers are not skilled enough for labor intensive natural dying process. Lack of
knowledge on natural dying process leading all the dying people to misunderstand the benefits of
natural dying process.
2. Lack of interest on shifting natural process from chemical process within field staff and NCVI
management that effects workers response to natural VATs dying process. It is important to
realize that the natural process should not be compared with hazardous chemical process rather
to understand why and how natural dyeing will benefit NCVI in future. Natural process takes
longer time than chemical process; natural process needs favorable natural and climate condition
that accelerate the dying process.
3. The existing VATs are appropriate for dying all sorts of fabrics for shibori and kantha but the
existing system does not allow to dye maximum length of fabric.
4. Natural VATs have been set up without sheep dung lining. In winter season, natural VATs will not
work properly due to cold weather from end of November to end of February .Sheep dung will
keep warm the VATs during winter season.
5. TDS and pH meter is out of order. Electrodes of both the meters are disorder.
6. laboratory grade fructose is found expensive and not good for regular use .
7. Poor quality indigo ( less purity) used in natural VATs that effects color and shade of the fabrics.

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4. Hands on training in order to build capacity on natural & fructose dying
for the dying group
a) Fructose dying:
An experiment on fructose dying was carried out with three variables of 10 grams, 25 grams and 100
grams indigo powder VATs as per instruction as provided . VATs prepared with expensive laboratory
grade calcium hydroxide, fructose and thiourea dioxide as there was no commercial grade available
in the local market. This dying is good for shibori and other small amount of fabrics on an urgent
basis.
b) Outputs:
• Four major different shade have been worked out in different types of fabrics from this fructose
VATs.
• Workers are trained on fructose VAT preparation and dying
c) Problems:
1. Commercial grade of all regents /chemicals are not available in local market. Laboratory grades
are only available which is very expensive.
2. Lack of gas burner, pressure cooker and other utensils for continuous boiling of water mixed
with indigo. Irregular or low fire hampered the fluctuation of pH of indigo parameters to get
actual shade during dying.
3. Lack of fine indigo powder (powder having granule) resulting non emulsification of indigo in to
water.
4. Lack of good set up with water supply facilities in the dying section.
5. Natural Dying & Indigo natural fermentation VAT preparation:
Natural VATs have been prepared with both earthen and plastic drum in dyeing section. The entire
dyeing section worker participated in the hands on training from starting phase to ending phase of
Different shade of fructose VAT dying in
silk and cotton fabrics
Shade of fructose VAT dying in cotton fabric

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natural fermentation VAT preparation. Natural VATs requires at least 21 days for full fermentation
and to be considered as matured for dying .Maintaining pH of each VAT is crucial and important for
different color shade preparation through every day follow up with adding lime for pH of the VAT. All
the ingredients are to be appropriate in weight and measures for each VAT at the time of
preparation. Day temperature is factor that responsible for changing of fermentation rate. A proper
insulation of sheep dung around the VAT is must for protecting cold effect in winter season
otherwise fermentation would be delayed even stopped for sometimes. However, A simple bangla
guide line is provided to the dying section people to follow the instructions & procedure of
recharging VATs in every week.
The following VATs have been set up in NCVI .
SL
#
Capacity Number of VATs Purpose Remarks
1 200 liters 2 ( VAT‐ 9,10) For maintaining different pH
range for dying shade and
wide length fabric dying
Maximum 5 meters length
of fabric can be dyed easily
in 200L plastic drum VAT.
2 180 Liters 1 (VAT‐!) Do Do
3 80 Liters 2 (VAT‐4,8) Shibori (Earthen pot VAT)
4 50 Liters 1 (VAT‐5) Shibori (Earthen pot VAT)
5 40 Liters 4 (VAT‐2,3,6,7) Shibori (Earthen pot VAT)
6 50 Liters 2 (Starter‐1 ,
starter ‐2)
Inoculums for setting up new
VATs
(Earthen pot VAT)
Total 12
Dying full length of cotton fabric (5 meters) Checking VAT pH before dying

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a) Dyeing : Natural VAT performance data.
Sample
number
VAT
number
pH of
VAT
Dying time/
dip time
Color before
wash
Color after
wash
Remarks
1 8 10 10 minutes Deep blue Deep blue
2 1 13 8 minutes Deep blue Deep blue
3 1 13 12 minutes Deep blue Deep blue
slightly reduced
color
Color was shining
4 4 11 5 minutes Light blue Reduced color
5 3 10 5 minutes Light blue Reduced color Matched with
provided shade # 4
6 Starter
VAT‐1
11 3 minutes Very Light
blue /pale
Very Light
blue /pale
7 3 11 7 minutes Faded blue Faded blue
8 7 12 2 minutes Pale blue Pale blue
9 7 12 2 minutes Pale blue Pale blue Matched with
provided shade # 3
10 Starter ‐2 10 3 minutes Pale blue
with leuco
indigo color
Pale blue
with leuco
indigo color
Matched with
provided shade # 2
11 Starter ‐2 11 3 minutes Pale blue
12 1 13 20 minutes Dark blue Dark blue Matched with
provided shade # 1
6. Work on setting an unit for dying maximum length of fabric (10
meters)
The experiments and practice of full length fabric natural dying have been carried out with three
different samples of 10 meters fabrics of cotton ( 2 dhuti and 1 twuil) in 200 liters of natural VAT
as instructed by Thomas. Three samples washed properly with boiled water and treated with soft
water and 0.1% vinegar solution.
a) Outputs:
• Full length of cotton ( 5 meters x 2 pieces ) fabrics have been dyed without any problem in 200
liters natural ( plastic drum) VAT . Color are evenly exposed and with no pachy. Oxidation for full
length fabric was properly done by hand which was manageable both for hand rubbing inside
the VAT .This length is feasible to work out the appropriate color as per shade.
• 10 meters twiul fabric was dyed in 200 liters VATs in 3 deeps methods. Color was not even
properly. Color was found as similar as per provided shade number 3.

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b) Parameters of four color shade (provided by Thomas)
Shade # VAT # Standard pH range Dip time
1 (dark blue) 1 13‐14 • 20‐22 minutes with hand rub
,fabric with dry condition.
2 ( Leuco indogo
color)
2 11 • 3 minutes with hand rub ,fabric
with dry condition.
• VAT fermentation age 15 days
3 (Pale blue) 7 12 • 2 minutes with hand rub ,fabric
with dry condition.
4 (yellowish blue ,
light leuco blue)
3 9‐10 • 5 minutes with hand rub ,fabric
with dry condition.
c) Oxidizing full length fabric :
Dying of full length fabric in plastic drum VAT Struggling in oxidizing the full length fabric
New method of oxidizing

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d. Final out puts:
• Total 40 meters of fabric have been dyed in 100% natural fermentation VAT. Each shade contains 10
meters of full length fabric
• A final color shade of all these fabric has been produced and available in dyeing section. All the
parameters have also been mentioned in the shade log sheet.
e. Problems.
• It was very difficult to handle and was unmanageable the full length of fabric for dying by hand
in 200 liters VAT.
• Hand rubbing was very difficult and was not possible to rub inside the VAT that created the
patch shade on the fabric
• As the fabric was so long it was quite difficult to oxidize at a time after pulling out from the VAT.
• Fabric was not washed properly because of any appropriate liquid soap and utensils at NCVI .
7. Recommendations:
a) Fructose dying;
• Buy a bulk amount of each reagent (fructose, theoria dioxide and calcium hydroxide ) as
commercial grade instead of laboratory grade .
• Arrange proper stain less still utensils/bowl of 20‐50 liters capacity for the washing & dying
fabrics.
• Arrange a good quality 2/3 chula/gas burner/ for continuous boiling of water for the dying.
• Dying people should continue of practice with fructose dying for shibori and other designs .
b) Natural dying.
• Immediate installation of tube well nearby dying room and construct a overhead tank with
capacity of 1000 litres ( 2 Gazi tanks) for water supply for both dying and washing purposes.
• Collect sheep dung and put around the VATs before winter coming. Please treat this as urgent.
• There should be straw made ceiling ( as instructed during training) over the natural
fermentation VATs.

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• Provide someone who will look after VATs , check pH, adding lime, arrange materials for
recharging VATs 7 days a week.
• Provide monthly salary to the main dyer (Shiuli and Mister) instead of day basis payment and
hope fully they would more concentrate in dying activities .
• Set up three more plastic drum VAT for natural dying in the dying section .
• Communicate with BCSIR, Dhaka and send pH and TDS meter with electrode for checking and
repairing.
c) Full length dying:
• Immediate construction of bricks made tank ( two tanks) with still roller for full length of fabric
dying inside the dying room.(diagram to be provided latter on)
• Proper SS made utensils for fabric washing before dying.
• Arrange quality liquid soap for washing for natural dyeing purposes.
• Arrange a device for oxidize full length of fabric with electrical fans.
• Provide full time worker for the purpose of full length dying.
8. Overall recommendations.
• Employ a proactive /experienced full time production Manager for NCVI to be responsible for
production of shibori section with the technical assistance of Kniz and over all responsible for
dying section to meet day to day production and requirement. Production Manager will assist
Mr.Sumontha,Chairman‐NCVI and Kaniz‐TO and other field staff who are involved directly with
production in the factory.