How to Calculate Fabric Shrinkage Percentage in Garment and Textile Industry?

The textile fabric has a common feature that it shrinks in wet processing. Shrinkage means the length of the fabric gets shorten after wash. So prior to cutting fabric for bulk production, you must check its shrinkage percentage in washing. The shrinkage percentage needed to add to the production pattern. Otherwise, you would not get garment of correct fit and measurement could not match the specification sheet.

This post will discuss how to calculate fabric shrinkage percentage by your own at home or in a factory. Step by step guide to calculating fabric shrinkage percentage is shown below.

Step 1: Prepare the wash test sample

Cut fabric from the roll and take fabric specimen of 110 cm X 110 cm (length X width). If you have multiple lots in fabrics rolls, take a sample from each lot.

Step 2: Measure before washing 

Mark a square of 100 cm X 100 cm (You can only mark + at the corner of the square.). Use fabric marker to mark the fabric. This is before wash measurement of fabric length and width.

Step 3: Wash the fabric sample

Wash the specimen following dip wash or machine wash as needed. Follow washing instruction provided by your buyers. Or follow standard washing method to find the shrinkage percentage to washing.

Step 4: Dry the sample after washing

Dry the fabric specimen as specified. Do line dry or tumble dry as specified in the test method.

Step 5: Measure after washing

Lay the specimen on a flat table. Remove creases but don't stretch the fabric. Measure the fabric length and width following marking points and note it.

Example: Let say, after washing measurement are as following

• Length wise measurement =95 cm 
• Width wise measurement = 97 cm

Now calculate shrinkage percentage specimen fabric using following formula

Fabric Shrinkage %= (Length before washing - length after washing)*100/Length before washing

Use data from the above example:

Fabric Shrinkage

Length wise= (100 - 95)/100 = 0.05 that is 5%
Width wise= (100 - 97)/100 = 0.03 that is 3%

Fabric Growth% Calculation

In some fabrics instead of fabric shrinkage, you may get fabric growth in length wise or width wise or in both directions. In that case, use following formula to calculate fabric growth percentage.

Fabric growth% = (Length after washing - length before washing)*100/Length before washing

If the fabric length increases after washing and the measurement after washing is 106 cm. Fabric growth percentage will be

= (106-100)/100 = 6%

Buyer Approved Garment and Textile Testing Labs

When it comes for quality standards for the apparel goods, physical properties of the fabrics, trims and accessories; presence of restricted chemicals in garments, goods must be tested from reputed testing labs. The test requirements vary according to the sourcing countries and product category. According to testing standards given by buyers garment and fabric exporters send samples to the buyer approved testing labs. Mostly known and buyers approved testing labs are listed in the following.

1. SGS 
SGS is the world’s leading inspection, verification, testing and certification company. SGS is recognized as the global benchmark for quality and integrity. This company operates a network of more than 1,250 offices and laboratories around the world.

Core services provided by SGS include:

• Inspection: Inspection and verification services, such as checking the condition and weight of traded goods at transshipment to control quantity and quality, and meet all relevant regulatory requirements across different regions and markets 
• Testing: Testing is done to reduce risks, shorten time to market and test the quality, safety and performance of your products against relevant health, safety and regulatory standards. 
• Certification: SGS also provide certification on products, processes, systems or services that are compliant with either national or international standards and regulations or customer defined standards. 

Site: www.sgs.com 

2. Intertek 
Intertek helps customers to assess their products and commodities against a wide range of safety, regulatory, quality and performance standards. 

Core services provided by Intertek include testing, certification, auditing, safety, quality assurance, inspection, evaluation, analytical, advisory, training, outsourcing, risk management, and security services. Testing covers a wide range of products such as textiles, apparels, soft home furnishings, leather, leather goods and luggage. Company works with 300 plus global retailers and brands. 

Site: http://www.intertek.com/ 

3. Bureau Veritas 
Bureau Veritas Group has consistently built recognized expertise, helping clients comply with standards and regulations relating to Quality, Health & Safety, Environment and Social Responsibility.

Services provided by Bureau Veritas include inspection, testing, auditing, certification, ship classification and related technical assistance, training and outsourcing. When appropriate, Bureau Veritas also provides advisory services. 

Large and small organizations, whether private or public, can rely on Bureau Veritas to support them in protecting their respective brands, assets and business. We play a key role in both risk management and performance improvement. 

Site: http://www.bureauveritas.co.in 

4. TUV India Private Limited 
TUV India Private Limited was established in 1989 as part of the German RWTÜV group's Indian operations. Being one of the first Certification Bodies to start operations in India, TUV India has been closely associated with the quality revolution in India. Starting with some of the earliest ISO 9001 audits by any certification body in India, TUV India, along with its parent group and CII, also organized some of the first Lead Assessor programs for capacity building in India. 

With a presence in over 30 locations across India, TUV India offers a comprehensive & diverse range of technical services to its large clientele.TUV India Pvt. Ltd. provides diverse services in Management Systems - Quality, Environment, Safety, Food, Information Technology, and Social accountability, Training in allied areas like Lead Auditor, Internal Auditor & Awareness Courses, Third Party Inspection, CDM & other Carbon and Energy services, Laboratory Testing (Analytical) services, PED/ASME certification, Product Certification (CE, GS marking ), Automotive Homologation, Six Sigma, CMMI etc. 

Site: http://www.tuv-nord.com/in 

Bill of Material (BOM) Format

What is Bill of Material (BOM)?

Bill of Material is a list of raw materials needed to be sourced to make a garment and make it ready for shipment as per buyer's requirement. In garment manufacturing, BOM is generally prepared by production merchants. Then has been approved by the responsible person and handed over to purchase department to start sourcing of raw materials.

A BOM normally includes items description, consumption (per piece consumption) with a defined unit of measure, projected cost per unit and total cost of each item. See the following format.

Fabric consumption and material consumption are calculated separately and added to the BOM sheet.

Bill of Material Format:

Following one is an example of the BOM format. BOM are prepared on a spreadsheet or by ERP.

BOM Sample sheet

Step by Step Guide to T-Shirt Manufacturing for Business

Are you interested in starting T-shirt business? Whether it is a manufacturing business or planning for starting your own t-shirt brand, you need to learn t-shirt manufacturing process. From design a t-shirt to shipping the t-shirt to retail store.

In this post I will discuss t-shirt manufacturing step by step – from order receiving to manufacturing a t-shirt in mass production. 

This post is completed in four parts

#1. Process flow for T-shirt making
#2. Step by step guide to order processing
#3. T-shirt stitching process
#4. T-shirt finishing process

1. Process flow for T-shirt making

The manufacturing process of t-shirt starts from designing a t-shirt, sourcing of fabrics and ends after selling the t-shirt to retailers. It is considered that design part is completed as buyer’s end and as a manufacturer you get order of a given style. For such orders, order processing involves following process flow.

T-shirt manufacturing process flow 

P.S. You can do garment sampling before starting the bulk production. Read this article to learn importance of sampling.

PPS: Many buyers provide instruction for stitching in techpack. Follow those instructions for workmanship, printing, washing, packing (if applicable). 

2. Steps by step guide for order processing

Here are the steps to be followed for making t-shirts (from order receiving to shipment).

• Once you receive the t-shirt sample with the order, analyze the garment and list down all detailing (construction, workmanship, seam, fabric used, trims attached etc). Estimate consumption of fabric and trims per garment. 
• Make bill of materials (BOM) after receiving the order. Include all items in the BOM. 
• Source Fabrics and trims as per requirement.
• After receiving fabrics and trims, check for quality and quantity of sourced items. Fabric and trims need to be checked as per specification (quality standards). For the confirmation for fabric properties you might need to send fabric sample to the testing labs. Test fabric shrinkage.
• Develop patterns for the style. Pattern grading to be done for different sizes. Make sample marker with actual garment patterns and find average consumption of fabrics.
• Make two/three sample garments and follow all processes to be followed in bulk production (e.g. washing and finishing). Check these samples after finishing. According to checking report of the sample do correction if needed. 
• This process will stop you making mistakes in patterns and shrinkage related issue in fabrics. Just to be safe from losing fabric and also maintaining quality of the final product.
• Start bulk process
• Lay fabric on the table as per marker length. Cut multiple layers at a time to save time in cutting. You can even layer multiple colors together. Just keep in mind to check size ratio. 
• Make marker on the top layer. Cut fabric as per pattern. Cut quantity to be as per size ratio in the in order. You can cut some extra garment for buffer. Like if some defective or rejected garment are made in the following processes.
• Check cut panels randomly for fabric defects and cutting is done according to the pattern.
• Make bundles of cutting (if required). Or you can feed complete layers to the sewing operator. 
• Set a group of tailors for stitching garments. Define sequence of the operations to be followed by tailors. Sew garments maintaining stitching quality. 
• Check stitching quality during sewing and at the end of sewing. Do correction of defective garment found in the line. Repair work (alteration and part changing job) can be done separately or by same tailors. 
• Send stitched garment to finishing section. Trim uncut threads. 
• Remove stains before pressing garments with steam iron (if stains are found in garments). If needed wash garments for cleaning and removing stains and getting wash effect. 
• Press garments.
• Fold garments. Attach hang tags and price tags to garments. Pack garments into poly bags. Pack garments according to customer requirement. 
• You can check finished and packed garment randomly for quality assurance. 
• Store packed garments for shipping to your buyers.

Note: In case you are making t-shirt for your own brand, you have to design the t-shirt, prepare techpack and you have to set quality standards. In that case order processing would vary. 

P.S. Your t-shirt design may have value addition like printing and embroidery design. So printing/embroidery process will be included based on the design at what stage printing to be done. Mostly printing of t-shirt is done on t-shirt panels. I mean after cutting, garment panels are sent to printing house for printing. After printing work cutting panels are sent to stitching floor. 

3. T-Shirt stitching process:

If you have not made a t-shirt earlier, you will be in dilemma on how to start making the t-shirt. I know you will be hiring tailors for making t-shirt and your tailors know how to sew the complete t-shirt. However, I want you to learn how to make the t-shirt from fabric panels. I have listed operation sequence to be followed making a t-shirt. I have also mentioned machine types to be selected for each operation. 

Buy one t-shirt as sample or pick one t-shirt from your clothes before you read following processes. Having one sample in hand you will understand quickly what I am saying here. A round neck t-shirt has 5 components 

• Front panel
• Back panel
• 2 Sleeves 
• Neck rib

List of operations involved in making t-shirt
In this section I have explained how t-shirt components are assembled step by step. 

#1. Shoulder Join: Join the both shoulders using an overlock machine. 

#2. Neck rib tuck: Join ends of the rib using a lock stitch machine. Neck rib length should be cut a per neck circumference. (A different method can be used for neck rib. In the following figure, neck piping is done first. After attaching one shoulder, neck is closed. )

#3.Neck rib join to neck: Fold the neck rib and attach to the neck. While attaching neck rib stretch both neck and rib. Attach neck rib using overlock machine and top stitch using lock stitch or chain stitch machine. Which machine to choose depends on the t-shirt design. (In case of neck piping, it is done using Flat lock machine).

#4. Label make: This process is optional. In case you have source main label/care label in the roll form, cut it and keep ready for the following process. Sometimes you may need to join more than one label together and later you will attach to the label to the t-shirt. A single needle lock stitch machine is used for this operation.

#5. Back Neck Binding/Neck tape: This operation is also an optional process. In quality t-shirt, you may show inside back neck overlock seam is hide by binding. For binding you need a binder (one kind of folder). A flat lock machine is used for binding. 

Instead of binding with self fabric, you can hide the back seam margin using a twill tape. Use a single needle lock stitch machine to attach the tape a back neck. 

#6. Front neck T/S: Top stitch the front neck using 2 needle flat lock machine

#7. Back Neck T/S: Finish neck binding using a single needle lock stitch machine. While finishing the back neck tape/binding, attach the size label. Follow the instruction provided in the techpack for position of the attaching size label. 

#8. Sleeve Hem: Hem sleeve opening in the flat lock machine. (Alternatively you sleeve hemming is after underarm overlock).

#9. Sleeve attach: Attach both sleeves at the armhole. An overlock machine is used to attach sleeve. 

#10. Side seam with care label: Join side seams and under arm using an ovelock machine. If you want to attach the wash care label, attach it left side of the garment, above 10 cm from bottom hem. 

#11. Sleeve Tacking: Tack sleeve at the overlock stitch to secure the stitch. Use single needle machine for this job.

#12. Bottom Hem: At last hem the t-shirt bottom using a 2 needle flat lock machine.

Sewing machine used in T-shirt making
Most common sewing machines used for making t-shirts are these.

• Single needle lock stitch machine
• Overlock machine 
• Flat lock sewing machine (Cylinder bed and flat bed flat lock)

Step by step stitching operations (assembling the t-shirt) are shown in the following chart. Stitching operations those are shown in the following infographic are based on a particular t-shirt sample (it may differ from above steps).

Infographic: T-shirt sewing process

4. T-Shirt Finishing Process

After stitching the T-shirt you have to finish it and pack (if apply) it prior to sending the t-shirts to retails store. Quality of packing and presentation is as important as the product quality. Following are process you need to do in finishing process. 

• Thread trimming: Trim all thread tails and remove loose threads.
• Quality checking: Check stitching quality. Follow the quality document for checking quality. In the finished garment fabric defects and stitching defects should not be allowed.
• Pressing / Ironing: Press all garments using a steam press. By pressing creases on the t-shirt is removed. 
• Folding: Fold the t-shirt according to folding dimension. 
• Tagging: Attach hang tags, price tags using tag-gun. 
• Packing: Pack individual t-shirts into poly bags. Or follow packing instruction from your buyer. See the following image for packed t-shirt.

This way t-shirts are made in mass production. In case you need further information you can contact me using by writing mail. 

P.S. I am planning to write an book on T-shirt manufacturing process  - all that you need to learn for starting t-shirt business from scratch. Please let me if you want (need) that book. Requesting you to write me on what contents should be covered on that book. Write me at prasanta@onlineclothingstudy.com

Machines Needed for Making Basic T-Shirts

I am often asked this question - What kind of sewing machines are required for making t-shirts. To reply to this question I have written this post. As you know t-shirt is a common apparel product and easy to make compared to other apparel products. To make quality t-shirt with good finishing inside and outside of the garment, you need over lock (for edge stitch), flat lock (for cover stitch) and single needle lock stitch machines.

Within the machine types there are various technology levels. You can decide which machine you need to purchase based on your requirement. Your machine supplier can advise you better. A same machine can be shared for multiple operations when you have few machines and you have low production requirement.

In the following table a machine requirement plan has been shown for production of 800 T-shirts in 8 hours shift (from a typical factory). Machine types and machine requirement in each operation has been also given in the following table.

Table-1: Operation wise machine types and machine requirement

Seq. No.	Operations	M/c Type	No. Of Machines
1	Shoulder join	4 Thread Over Lock	1
2	Neck rib Tuck	1N Lock Stitch	1
3	Neck Join	4 Thread Over Lock	2
4	Label Make	1N Lock Stitch	1
5	Back Neck Binding	Flat lock/1NLS	1
6	Front Neck Top	Flat lock	1
7	Back Neck Top	1N Lock Stitch	2
8	Sleeve Hem	Flat lock	1
9	Sleeve Join	4 Thread Over Lock	2
10	Side Seam	Flat lock	2
11	Sleeve tuck	1N Lock Stitch	1
12	Body Hem	Flat lock	1
Total			16

Disclaimer: The machine types and number of machines mentioned here are based on particular situation and shared here for information purpose only. This machine quantity may not match for your set-up.

Double Jersey Types

Double Jersey Types

Double face / Mattress

Spacer

Fine Gauge

Elektronic Jaguard

Transfer

Stripper

Rib Structure

Interlook Structure

Body Size

Single Jersey Types

Single Jersey Types

Single Jersey Plain Structure
Mesh
Plush/Polar Fleece
3-threaded fleece structure
Finge gauge
Elektronic Jacquard
Stripper
Body Size
Mini Jacquard