How Does a Fabric Shrinkage Test Impact the Quality of Garments?

When it comes to garment manufacturing, fabric quality is paramount. Among the many factors that influence a fabric’s overall quality, shrinkage is one of the most important to consider. Shrinkage can affect the fit, durability, and appearance of the final garment, ultimately impacting consumer satisfaction and brand reputation. For this reason, fabric shrinkage testing is a crucial step in the quality control process for apparel manufacturers.

In this blog, we will explore how fabric shrinkage tests impact the quality of garments and why every textile manufacturer should prioritize this process.

What is a Fabric Shrinkage Test?

A fabric shrinkage test is a procedure used to assess how much a fabric changes in size after being exposed to specific conditions, such as washing, drying, or other environmental factors. The test measures the dimensional changes in the fabric before and after these processes, helping manufacturers predict the final garment's fit and performance.

Shrinkage can occur naturally due to the fibers' reaction to water, heat, or pressure during the washing and drying process. Therefore, fabric shrinkage tests help evaluate how a fabric will behave during regular use and after multiple wash cycles, ensuring that the final product meets customer expectations.

Different Types of Fabric Shrinkage Tests

Various fabric shrinkage test methods can be used depending on the fabric type and the intended end use. Some common methods include:

• AATCC Test Method 135: Measures the shrinkage of woven and knitted fabrics after laundering; commonly used in the apparel industry.
• ISO 6330: An international standard test that simulates domestic washing conditions to determine fabric shrinkage.
• Drying Shrinkage Test: Assesses how much fabric shrinks when exposed to drying conditions without washing.

How to Minimize Fabric Shrinkage

While some degree of shrinkage is inevitable, there are several strategies that manufacturers can use to minimize its impact:

• Pre-Shrinking: Fabrics can be pre-shrunk during production to ensure they don’t shrink too much after purchase.
• Use of Shrinkage-Resistant Fibers: Some fibers, such as polyester, are less prone to shrinkage and may be preferred in garments where shrinkage control is critical.
• Proper Washing Instructions: Clear care instructions on the garment label help consumers avoid excessive shrinkage by following recommended washing and drying methods.

How Fabric Shrinkage Affects Garment Quality

Fabric shrinkage can significantly impact several aspects of garment quality, including fit, appearance, and longevity. Below are the main ways shrinkage tests influence garment quality:

1. Ensuring the Proper Fit

One of the most important aspects of garment quality is how well it fits the wearer. Shrinkage can cause a garment to become too tight or too loose, leading to discomfort and dissatisfaction. This is especially critical for fitted clothing like shirts, dresses, or trousers.

By performing a fabric shrinkage test, manufacturers can anticipate how much the fabric will shrink during its lifetime and adjust the garment's pattern accordingly. For example, a fabric that shrinks by 5% after washing can be pre-shrunk during production to ensure the final garment size remains consistent.

Common Practices Followed by Garment Manufacturers to Control Fabric Shrinkage

2. Measure Fabric Shrinkage and Add Shrinkage to the Pattern

Garment manufacturers cut swatches from all fabric lots and send them for testing. Two common processes include:

• Fabric Swatch Test: A 100 x 100 cm fabric swatch is cut, marked, washed, and measured to calculate shrinkage.
• Blanket Form Test: A blanket with three sides closed and one open is washed and shrinkage is calculated.

3. Relaxing Fabric Prior to Cutting

Manufacturers relax fabric overnight after opening the roll, and again after layering it on the cutting table. This ensures stability before cutting begins, even when shrinkage has been added to the pattern.

4. Cut Panel Laundry (CPL)

In knits, the fabric may shrink and twist post-wash. CPL involves cutting fabric panels and washing them before bulk production to preshrink the material. This eliminates the need to modify base patterns or relax fabric again.

Shrinkage Formula

Shrinkage % = ((Length before wash – Length after wash) / Length before wash) x 100

Example:
Length before wash = 35 cm
Length after wash = 33 cm
Shrinkage % = ((35 - 33) / 35) x 100 = 5.7%

Normally, shrinkage of less than 5% is considered acceptable unless the buyer specifies otherwise.