Thursday, 28 February 2013

Indian Ethnic Fabric Buying- Evaluating Vendors

Evaluation of the vendors for Indian Ethnic Fabric is more of an art than a science simply for the fact that there are many soft factors involved. Indian ethnic fabrics are masterpieces generally belong to a particular community who has perfected the art of producing it traditionally. When it comes to dealing with small volumes, you can get very good quality. But the moment the volume go bigger and is limited by delivery timelines, all sort of problmes start happening. Hence it is important to know your vendor before an order is placed with him/her. Generally the crieteria revolves around dealing with the vendors for a few years before making any evaluation.
Time of association with the company is a very important factor. The older the vendor/artisan is with a company, he understands the modus operandi of the company, the likes and dislikes and adept itself to work in the way. This leads to saving in time when explaining designs and fewer rejections.
Volume and value of the fabric done per year is another factor that needs to be looked into. More volume done with the company indicates the vendor's capacity. Evaluating capacity of an artisan is very different from evaluating the capacity of the mill wherein one can count the number of machines and multiply by speed and efficiency to get the capacity. Generally artisans work in small clusters and the looms/printing tables are distributed over a wide geographicaly area. If a vendor can deliver volume that indicates his relationships with the vendors and his financial strength. In case of Tussars/Bhagalpur silks this is of critical importance as the greige fabric has to be booked in advance of one year and colors are indicated closer to the season. The vendor should have the financial strength to hold on the stock for that period. 
Innovative designs shown and converted every year is the vital factor for a vendor. It ensures that his margins keep on increasing, his development costs are low and the company is invigorated by the infusion of new designs. Normally, the time of association with the company determines this factor. Block printing can be done on various textures of the fabrics available. Similarly the designs from the saris can be translated into dupattas and stoles after suitable modification. This ensure that the story of the brand is intact and the same language is conveyed to the loyal customer who flock to the stores to get the quintessance of the the brand.
A vendor becomes important if the designs shown by him are impossible or difficult to reproduce anywhere else. That ensures that he gets his desired price points and can dicate terms with regard to production or delivery. It happens in case of traditional wovens and prints that are produced using indiginous techniques like Bagru, Dabu, Jamdanis, Chanderi and Sanganeri Butis.
--To be Continued in the Next Post-----

Sunday, 24 February 2013

Supply Chain Risks in Indian Ethnic Garment Buying

Managing ethnic garment supply chain is very challanging as the various people involved are geographically and culturally very diverse and the conditions keep on varying all the time. To forecast and manage the supply becomes very complex as so many factors are involved, I have listed a few factors on which supply chain faces challenges

1. Disruptions

These happen in cases where the design is dependent on the supplier and the lead time is more. As an example there is a supplier of chikankari based in Lucknow, and she embroiders the panels which are cut in Delhi. Whenever she goes on leave for a weak, the whole schedule takes a tumble.Also disruptions take place in South during Pongal and in North India during Eid and Diwali. All these will break the supply chain down. Some of these for example festivals are predictable and precautions may be taken, but the impact is not predictable. For example, we can plan that the production may reduce to half during festive time, but it may as well reduce by 3/4th, which make planning very difficult. For Bhagalpur fabrics, in Monsoons, no dyeing is possible and Monsoon is not predictable. To avoid that the dyeing needs to done before June for the piece dyed fabrics.

Disruptions are also caused when a supplier cannot give the required quality asked.

Disruptions are also caused by the demand. Sometimes the demand go up which cannot be met given a particular lead time for the fabrics and the processes. Sometimes it goes down which may have an impact over the stock situtation at the stores and the suppliers.

Generally this risk is avoided by keeping adequate inventory of high volume high value items. More suppliers are developed for the same product and redundancy is created to overcome the risk. However keeping inventory intelligently is a juggling, a manager is doing always.

2. Delays

Delays happen for all the reasons. Sometimes the styles get closed late. The order can get delayed because of the apporvals of the production and various samples. Orders also get delayed due to interference effect, when a supplier takes the quantum of the orders he cannot digest. Delays are prevented by adding inventory, taking higher lead time and choosing flexibility in the suppliers.

3. Systems

Supply chain also gets broken down by the failure systems, though it rare. This happens when the ERP and computer system doesn't work for sometime.  During inventory checking, no transaction happen and this is a supply chain risk. This risk is mitigated by the manual methods of logistics.

4.  Information Processes

There is a risk when after taking an order, the supplier increases the minimum order size, increases the rate and downgrade the quality. It also happens when sometimes suppliers get inundated with work and sometimes no work so they cannot plan properly.

5. Procurement

There is a risk when supplier increases price, the price of freight increases and sometimes there are inordinate delays in payment to the supplier due to some reasons. This is normally prevented by signing long term contracts, building relations with supplier and using multiple suppliers.

6. Inventory Risk

To manage all the risks above, keeping the right inventory is very vital. But inventory keeping itself is frought with risks. Generally inventory risk is dependent upon three factors: The value of the product, its rate of obsolescence and uncertainty in demand and supply. To manage it the following statragies are used:

- Pooling the Inventory: This is used in case of high value fabrics which are used all across the categories. For example for high value wild silk varieties which are piece dyed, the demand for the greige fabric is aggregated and then orders are released to the suppliers.

- Creating Common Components and Postponing and Delaying the production until all orders are in hand. As in the previous example the order for greige fabric production is given six months in advance to the supplier and the orders for colors are releasd very close to the season.

Needless to say, supply chain management is very complex for Indian Ethnic Garment Retailing as the various weavers and printers are located at diverse locations and under diverse conditions.

Further Readings

Saturday, 23 February 2013

How Garments are Dyed Commercially

The garments can be dyed by using pigment dyes. Previously it was condsidered that pigment dyes were non chemically reactive to any fiber. Hence padding or printing with a binder was used. However, now a cationic binder is exhausted onto a garment. This creates an affinity for the garment by the pigment. Then pigment dyestuff is added.
Once the pigment dyeing is completed, the garment is rinsed. Then a low temperature or air curable binder is applied to the garments to improve the colorfastness to rubbing.
The fastness to rubbing for these colors is satisfactory. However, the colors will washdown during the life of the garments. The higher the concentration of the color, the poor is the colorfastness to washing. However, they have excellent colorfastness to light.
Please see the complete process here.

Sunday, 17 February 2013

Why some prints smell of Kerosene

This smell is normally observed in pigment printing. 

In pigment printing, thickener is used. Two types of thickeners are common. One is emulsion thickener, which has zero solid content in it. This is obtained by emulsification of two immiscible liquids with the help of the emulsifier. Generally Oil-in-water emulsions are used.

A typical recipe of pigment contains 100 parts of binder, 100-150 parts of water, 20-parts emulsifier,  Kerosene or Mineral Turpentine Oil ( MTO) is used which is 750-800 parts. Apart from this 20 parts Urea is added  as hygroscopic agent and 4-6% paste of CMC (10 parts ) is added which acts as a protective colloid. The recipe is ideal for pigment printing. However it suffers from demerits such as inflammable fire hazards, air pollution, high costs and most important of all is the smell of the fabric which is due to residual Kerosene Oil or MTO. To counter these synthetic thickeners are used. These are high weight copolymers of acrylic or methacrylic acid. They come in acid or neutralized form. They do not suffer from drawbacks of the emulsion thickeners, however, they suffer from dull prints and harsh fabric feel.  Also the drying time is longer.  

There are some printers who feel that with synthetic thickeners, there is always a concern of colors spilling over when working with very fine intricate designs and they prefer to use MTO or kerosene. 

Friday, 8 February 2013

How curing is important in pigment printing

A pigment has no affinity to fiber. It is insoluble in water. It needs binder for fixation onto fiber.  A binder is a prepolymer available in the form of aqueous emulsion. Chemically it is copolymer of UTYLACRYLATE-N-METHYLOL ACRYL AMIDE.  Mechanism of binding involves the following sequence: PRINT > DRY >CURE. During curing, the binder polymerises and forms a strong film.  The film embeds pigment color and also strongly adheres to the fiber. Curing is done at 150 degrees for 4-5 minutes. When curing is not proper the poor wash fastness and poor colorfastness will result. Assuming sufficient binder was added to the color paste, these problems are usually resolved by repeating the heat exposure ( Re curing)

Wednesday, 6 February 2013

Some Notes about Bleaching

Effect of Metals on Hypochlorite Bleaching

Copper and Iron catalyze the oxidaton of cellulose by Sodium hypochlorite degrading the fiber. Fabric must be free from rust spots and traces of metals otherwise bleaching will damage the fabric. 

Stainless stell equipments should be used and care must be taken that the water supply is free from metal and rust from pipes. Prescouring from chelating agents become an important step when bleaching with sodium hypochlorite. 

Weight Loss of Fabric in Bleaching

After bleaching operation the weight loss in the material takes place and it depends on different types of bleaching agents that are used. Due to the removal of coloring matters and fiber damage in the bleaching, textile material may lose considerable weight. In a study it was found that in plain weave fabrics, the weight loss was upto 11% for Sodium hypochlorite bleach and upto 8% in Hydrogen Peroxide bleach.





Saturday, 2 February 2013

Buying of Indian Ethnic Fabrics- Weaving Issues

Weaving flaws come naturally with Indian traditional fabrics. Some of these are inevitable and some of these are avoidable. Below are the details of the common weaving issues that come with the Indian traditional fabrics:

Fabric Weight
Weaving defects in the traditional fabrics arise due to techniques used in weaving them as well as the manual operations involved in it. They also occur as the quality of yarn used in warp and weft is compromised or the yarn itself is handspun. In Handloom fabrics, the usual defects are holes, mending, missing end and missing and broken picks. The fabric weight also varies as the fabric is getting woven with variable beat up depending upon the person and also varies during the course of the day of weaving. In the morning, the weaver is fresh, and the beat up is more compact. As the day progresses the picks may spread farther apart.
From the facts given above, it can be inferred. The usual method of finding GSM by using GSM cutter is no longer valid when evaluating handloom fabric. The best way to evaluate is to weight it thaan by thaan and average it out. 

Chira ( Missing End)
This effect occurs in all the fabrics, but it is more severe in powerlooms which are without warp stop motion. Chira is not prevalent in South looms as they are equipped with warp stop motion. However, for woven fabrics of north India, it is quite a common defect. 

Banding in the weft occurs due to particular contrast of colors, it is more visible in fabrics with cross colors. Also banding is visible when yarns are hand dyed and after the finish of one pirn, the next pirn contains different dyed lot of yarn. It also is visible in dyed fabrics when the count in the weft changes appreciably. It is more common in Khadis where the yarns of weft ( Amber) come in different lots. 

Tight End and Reed Mark
This forms a series of warp wise faint lines in the fabric. It occurs due to uneven tension in the warp beam which can happen when making the warp beam manually. It also occurs due to not cleaning, damaged heald wires or some problems in the reed. Often reed marks come in these fabrics. 

The main cause of holes is the pointed scale used all across the country to measure the length and fold the cloth. If a center point is used to hold the fabrics, and the point gets blunt it can cause appreciably visible holes and sometimes makes the whole fabric amenable to rejecting. 

Slippage of the Warp or weft ends
This takes place in almose all the fabrics loosly woven but it is more appreciable in silks and especially unions of silks with Viscose. The unions from Bhagalpur are more susceptible to this defect. To counter this the fabric after weaving is given a special starch finish, but that too is unsustainable and gives way in three or four washes. The cause of this defect is the smooth surface of viscose which can slip easily on silk. This damage leads to seam slippage which is easily noticeable in the stress areas of the garment(neck and arm whole) The solution is to improve the construction of the fabric or use a better quality viscose. To control this problem in garments at the nect, moon patches are applied

This defect is observed in handloom fabrics which use handspun yarn. Based on the quality of roving they are using these will contain foreign fibers which do not catch dyes leading to this defect. 

Rough appearance
Rough appearance occurs due to the nature of yarn. In most of the cases carded yarn is used, which contain short fibers which come at the top in the process of weaving. This also due to the uneven count of yarn and slubs present therein. This defect is not a defect as such rather than a mark of true ethnic fabrics. Moreover, hand feel of two garments made from identical fabrics will be different as they may be woven on different looms and subject to different treatments.

Pilling in cotton fabric is observed in cross colors where one of the yarn is of dark color. The short fibers come to the surface and form a pill type structure. This defect is aggravated when one of the yarns is sulphur dyed. This is also present in Matka silk which is handspun and handwoven. In yarn dyed Matka, the problem is further aggravated. Silk Noil fabrics are also a victim to this defect as they by default contain short fibers.  

Friday, 1 February 2013

Buying of Indian Traditional Fabrics- Dyes

Every region of India comes with a characteristics of technique of textiles that has perfected one particular class of dyes. For a buyer it poses a significant challenge to maintain the quality of fabrics over time as each class of dyes has its own strength and limitations. 

Napthol Color

All over in south and in Bengal, Napthol colors are used to dye Ikats and Cottons. Generally vat colors are used to dye the dull shades. However, to achieve the required saturation in the darker shades, napthol colors are used. Due to process restrictions and the conditions when dyeing locally, the colorfastness to rubbing is a big problem when working with these colors. A case needs to be pointed out in this regard. When asked about the colorfastness issue for a certain sari from a vendor, it was found that even after washing the yarn after dyeing and washing the fabric after weaving, the colorfastness to rubbing was not improving for napthol dyes. Napthol colors are also being used in Maheshwari Saris for red and other dark colors.

Please see also the following links in this regard:

Vat Colors
Vat colors are the most commonly used colors all across the country in dyeing traditional fabrics. Vat colors are easy to apply, the process can be done at a temperature achievable in the open furnaces. The colors are fast to rubbing and washing. The main issue is in the achieving of bright and saturated shades which vat colors cannot produce using ordinary condition.

Sulphur Colors
Sulphur dyes are often used to dye black. Cheaper and easy to apply, they have a very good colorfastness to washing. The drawback is that the fabric starts to tear after a prolonged storage.

Reactive Colors
Reactive colors are increasingly being used in woven yarn dyed stripes and dobbies, thanks to the chambers used in dyeing hank yarn. They have good colorfastness properties overall.

Direct Colors
Direct dyes are used extensively in the Indian traditional textile industry. These are easy to apply and cheap. Almost all the tie and dye fabrics whether, Bandhni, Lehariya, Mothra, Ikat and  Shibori have these dyes. These are also being used in the Tussar/Viscose blends in piece dyed form. The colorfastness to washing is good or acceptable but to that of rubbing is poor. A challenge for a bulk buyers of the fabric of these dyes is to convert the dyers to reactive or vat dyes.

Acid/Metal Complex Colors
These are used in pure silk and wool. They pose no problems for the buyer. These are colorfast to washing and stable to fading. 

Natural Dyes
Natural Dyes are obtained from plant extract. The problem with natural dyed fabrics is that the volumes cannot be obtained and quality is not consistent. Patchiness, tonal variation across the length and listing ( Center to Selvedge variations) are some of the defects that come naturally with natural dyes. Also the choice of colors is limited to a very restricted pallete; beige, black, maroon, mustard, rust, green and indigo are the colors that can be got in these dyes. Color fastness is a big issue with these dyes. These are often sold in the market with the disclaimer tag. 
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