What is Lab Dip | Objects of Lab Dips | Process Sequence of Lab Dip

Lab Dip:A lab dip is a swatch of fabric test dyed to hit a color standard. It is a process by which buyer’s supplied swatch is matched with the varying dyes percentage in the laboratory with or without help of spectrophotometer. Lab dip plays an important role in shade matching & this is an important task before bulk production. In previous article of this author we have to learn on flow chart on dyeing lab.

Lab dip

There are different matching systems followed in Labs. They are   :

1. Tube light matching.2. Sun light matching.3. Ultra Violet matching.4. Sodium light matching (show room).

Object of Lab Dip:   The main objectives in lab dip are as follows: 

1. To calculate the recipe for sample dyeing.2. To compare dyed sample with swatch by light Box or Spectrophotometer.3. To calculate revise recipe for sample dyeing.4. Finally approved Lab Dip (Grade: A, B, C & D)

Process Sequence of Lab Dip:   Lab dip plays an important role in dyeing process. Bulk dyeing process completely depends on the lab dip development work. Lab dip is completely managed as the following sequence. 

Lab Dip Requisition from buyer 

↓ Entry in the computer 

↓ First recipe is given by swatch/pantone number 

↓ First correction 

↓ Second correction 

↓ Grading of sample (A, B, C, D) 

↓ Yarn and knit sample send to buyer 

↓ Approved by buyer 

↓ Order for bulk production 

↓ Production card with approved sample and recipe send to production section. 

Lab Test for GarmentsAccording to the buyers’ testing requirements garments, fabrics, yarn and accessories (zipper, button, eyelet etc.) need to be tested by the buyer approved testing labs to ensure that the goods maintain quality standards and there is no presence of restricted chemicals in garments and accessories.

The labtest requirements vary according to the buyers, sourcing countries and products. For labtest, testing laboratories require samples of garments, fabrics, yarn and accessories. Properly filled up test forms of the respective laboratories need to be submitted with the items. Some laboratories require their test forms to be filled up online. Merchandisers need to be very careful to fill up the forms. Samples need to be tested in different stage of production such as fit/pp/production etc. It should be clearly mentioned which samples are going to be tested as test reports are prepared according to the test form information. Style no, po no, product code no, color name & code also should be mentioned as per PO sheet. Labs do not take any liability if test forms contain incorrect information. List of some lab test requirements are as follows:

SL

Test requirements

1 Measurement test

2 Fabric construction test

3 Dimensional stability test

4 Fiber content test

5 Yarn Count test

6 Tear strength test

7 Weight of material

8 GSM test of the fabric

9 Shrinkage test

10

Color fastness test

11

Rubbing fastness (dry and wet)

12

Color bleeding test

13

Pilling test

14

Azo test

15

Nickel test

16

Lead test

17

Magnet test

18

PH Test

19

Tests for care & wash instruction

Mostly recognized and buyers approved testing labs are –

NAME WEB

SGS www.sgs.com

Intertek www.intertek.com

Bureau Veritaswww.bureauveritas.com

TÜV SÜD www.tuv-sud.com

Consumer Testing Laboratorieswww.consumertesting.com

10 important things for a merchandiser for lab dip approval 

Developing Lab dip is one of the primary jobs for a merchandiser to start an order

execution. They need to run for lab dip approval. Though this would be an easy task,

sometimes big mistakes may occur. The present article will help everyone in dealing with

lab dip who works as merchandiser or hope to start career in merchandising. It is to be

mentioned that this article is not focused for dye houses or laboratories. They definitely

need to know the merchandisers perspective but of course they have many other

perspectives.

1. What is a lab dip?

Lab dip is small swatch of fabric to define color and its recipe before it goes for bulk dyeing.

This is also a master piece for both buyer & manufacturer that give correct source what to

be color look like and what is the corresponding dyestuff recipe would be. Lab dip is

important because different combination of dyes or different color recipe produces different

shades. The dye houses matches their lab dip with buyers’ reference colour. Buyers’

reference for colour or shade can be anything like a piece of fabric or pantone number. This

reference is called standard. Lab dip typically done by size 6x6’’. For each fabrication it

needs to do separate lab dip for approval. Fabric or material on which colouration is being

done is important and so lab dip fabric has to be same one as the bulk fabric where the final

colour will appear for garments making. Lab department use their specific reference

number on each lab swatch to define the color & recipe. Usually factory use as shade

A,B,C,D in 3 to 6 options of color shade .For lab approval better to use minimum four

options so that buyer can find exact color which is closer to standard. In the submissions

given to buyer the dye houses usually don’t give details recipe but they conserve that

information at their end for their further operations.

2. Lab dip & light source

Light source is very important to understand shade rightly. Light source its cabinet and

viewing angles all are important factors in colour matching. The box that contains the light

sources and which is facilitating right environment with options of viewing angles for colour

matching is called light box. Customer or buyer shouldrightly mention what light source

they prefer for color checking. Usually below light sources are used to match color. Each of

the below matching conditions may give different results.D-65&TL84is used by most of the

buyers.� So a good light box is required to match color & shade.

1. Artificial Daylight Fluorescent Lamps (D-65)

2. Tungsten Filament Lamps.

3. Tri Phosphor Fluorescent Lamps (TL84).

4. Ultra violet Black Lamp (UVB).

5. Cool White Fluorescent Lamp (CWF)

Some customer has requirement for spectrometer to match color. Spectrometer is a

machine & electrical data to identifying and matching color, tone or hue. This is very costly

& not user friendly. Proper expertise is needed for proper use of such equipment.

Usually buyers consider point of sale lighting condition and point of use lighting condition

for colour matching. D 65 refers to point of use light source while TL84 refers to point of

sale light source.

3. Colour standard?

Color standard is a piece of fabric or a pantone number provided by buyer to manufacturer

for making lab dip. This may be a cut of garment or swatch from buyer’s collection. Buyer

selects some colors for each season like summer collection, autumn/winter collection, and

winter collection so on. Based on this collection they develop lab dipcolours to be used for

bulk. To get a color collection buyers usually do market survey & follow the colour trends of

the season. So all time they may not provide you correct standard for lab dip. Because

some time buyer cut the color swatch from best seal garment from his own brand, this will

not help you all the way. A finished garment cannot be good standard for lab dip making.

Lab dip is not final out of color for a garment. This is standard for dyeing color of fabric but

not garment. Final color for garment may be different if it has some washed application or

any extra finishing. So merchandiser or lab concern should aware & must inform customer

that final garment swatch is not correct standard for making lab dip. Sometimes Buyer

gives pantone number as color standard.

4. Confirm Fabrication before making lab dip

Fabrication is important because color gets different on different fabrication. So

merchandiser or lab in-charge must confirm fabric composition beforehand & its type also.

As mentioned above single jersey lab dip cannot be approval for 1x1 fabric type. Similarly

100% cotton fabric cannot be for cotton/elastane; plain jersey cannot be for slab jersey.

Suppose if buyer wants a shade on 100% cotton & giving a shade in mixed fiber then

rejecting the lab dip each time for not matching shade. This is actually not for color

percentage but for composition .A mixed fiber shade may also vary for its percentage. So

before making lab dip, confirm composition. Without confirming the composition if you go

for lab dip every time it will be rejected.

5. Dyestuff and dyeing process used for lab dip preparation

Dye type is important because each type of dyeing has different recipe. Some time buyer

may not tell you the dyeing process but you have to confirm before making the lab dip. Or

some time you have to identify the dye type base on your final garment process. If garment

has discharge print you must do discharge dye though buyer ask for reactive dye. Suppose

you make lab dip in reactive dye & as usual buyer give approval then make fabric but no

one was aware of print technique &when go for discharge print you see nothing is

happening. Because discharge print require discharge dyedfabric. Discharge prints actually

burn the fabric color &stay on the place. So by doing reactive dye you cannot achieve

discharge print. On the other hand discharge dye a bit costly than normal dye. That means

you will do big wrong in calculation & fabric dyeing.

6. All Over Print (AOP) lab dip ; consider light ground

Many merchandisers do mistake by taking approval on body color for AOP. Actually for AOP

need to consider light ground for lab dip or fabric color. Suppose AOP has five color

including ground. If ground is dark color & consider for print it will be wrong .Because AOP

cannot be done on dark color. On red color ground not possible to do white print but on

white ground red can be done nicely. So this is good to take always light color or white for

AOP. If no light color is found to consider ground for print take white ground for fabric color.

In this case total print color will be five & ground color white will not be visible. So it will

affect your price also if you consider four color prints during price negotiation.

7. Yarn dip & its time

Yarn dip is same as lab dip just in yarn form, done for yarn dyed fabric. Yarn dye process is

very lengthy & not easy to make frequently. So yarn dip also takes little longer time than

normal lab dip. If normal lab dip can be done by a week, yarn dip requires minimum two

weeks to prepare.� Here merchandiser must calculate days from 1st yarn dip submission

to approval, revised submission if require altogether 30 days minimum & some time more

than this. So make sure to give priorityfor yarn dip submission & consider maximum time

that require for approval.

8. Lab Dip Process for Garment over dye

If Garment has over dye program lab dip has to be done in different form. Over dye lab dip

is not exactly same as general lab dip process. As garment has to put in the washing

machine for dye & can achieve vintage look the lab dip also require doing in the same

process. Big sizes fabric panel sewn both side like a bag keep in the machine & dye it. This

panel is used as lab dip for garment over dye & for the next step. Recently some washing

plant established lab machine for development but this is actually not available in

Bangladesh.

9. Foreign Lab dip

Foreign lab dip means if you are going to buy fabric from foreign country that time you

have to take lab dip approval also. To take foreign lab dip approval merchandiser must

keep close monitoring. See how foreign lab dip requires time �

1. Merchandiser receive standard from buyer.

2. Then courier the standard to supplier for making lab dip.

3. After that Supplier take minimum two weeks to make it.

4. Send it to merchandiser.

5. Merchandiser reviews it & send to buyer.

6. Buyers receive the lab dip then givecomment.

7. If 1st submission is approved that makes easy for bulk.

8. But if not then again start the lab dip cycle & wait for approval.

From the above process we see for foreign lab dip need to get approval at 1stsubmission. If

2nd or 3rd is required definitely all the process will be delayed. So merchandiser must be

aware to send correct standard in due date & tell supplier to do lab dip properly. Some time

it is suggested to send lab dip directly to buyer from fabric supplier. It will save at least one

week on all the process.

10. How to store Lab dip

For a merchandiser or lab concern this is very important to keep the lab dip in secure place.

The below idea can help to keep it.

1. Keep lab dip inside a plastic bag.

2. Keep away from light.

3. Keep it in secure place away from all kinds of dust.

4. Put date on every submission so that lab dip can be identified in sequence.

5. Attach buyers comment on each submission.

6. Finally put approved mark on approved shade.