Why Does Fabric Weight Decrease After Dyeing?
- Intan Jaya Tekstil
- Mar 12
- 3 min read
If you re-weigh fabric bought from a shop, the weight often doesn't match the label. How can that be? Let’s break it down...
Understanding Gross and Net Weight in Cotton Fabric
In the textile industry, especially in the cotton jersey trade, two important terms frequently appear:
Gross Weight
Net Weight
For those in the convection and garment business, understanding these terms is crucial because they directly affect:
Fabric requirement calculations
Production cost estimations
Transaction transparency with suppliers
Many new buyers are confused when they find that the fabric weight after the dyeing process is lighter than the initial weight. In reality, this is a normal process in the textile industry.
Let’s discuss this simply.
What is Gross Weight in Fabric?
Gross weight is the weight of the fabric before it undergoes the color dyeing process. At this stage, the fabric is still "greige"—raw fabric that has just finished being knitted from yarn.
Characteristics of fabric in a gross state:
Unwashed
Has not undergone bleaching
Undyed
Contains knitting oils
Contains natural impurities from cotton fibers
Because it still contains these various residues, the gross weight is usually heavier than the weight after finishing.
What is Net Weight?
Net weight is the weight of the fabric after all dyeing and finishing processes are complete. Before fabric is ready for garment production, it usually passes through several stages:
Scouring: A washing process to remove knitting oils and impurities from the cotton fibers.
Bleaching: A whitening process to remove the natural color of cotton. This stage is usually more intense for white fabrics.
Dyeing: The process of soaking the fabric in the desired color.
Finishing: The final perfection process to ensure the fabric is stable and ready to be made into clothing.
During these processes, some of the fabric's natural components are lost, causing the weight to shrink.
Why Does Fabric Weight Shrink?
There are several main causes of weight loss after dyeing:
Loss of knitting oil: Oils used during the knitting process are washed away.
Loss of natural cotton wax: Cotton fibers naturally have a wax layer that is removed during scouring.
Bleaching process: For white colors, bleaching lifts more natural material from the fabric.
Repeated washing: Several production stages involve multiple wash cycles.
Consequently, the weight after finishing is typically lighter than the greige weight.
What is Normal Weight Loss for Cotton?
In textile industry practice, cotton fabric typically has a weight loss tolerance of around 8%. For white colors, shrinkage can reach around 10% because the bleaching process is more intense and no additional dyestuffs are added.
It is important to understand that these figures are not official regulatory standards, but rather benchmarks formed by consistent production history in the industry.
Example of Weight Loss Calculation
Imagine a fabric with the following conditions:
Weight | |
Weight before dyeing (Gross) | 25 kg |
Weight after dyeing (Net) | 24 kg |
Shrinkage calculation:
((25 - 24) / 25) x 100% = 4%
This means the fabric experienced a 4% weight loss. This figure is very good as it sits well below the industry tolerance of 8%.
How Does This Affect Fabric Price?
Because the weight shrinks after dyeing, fabric prices are usually calculated by considering this shrinkage tolerance.
Example:
Gross price: Rp 100,000 / kg
If shrinkage tolerance is 8%, the net price becomes Rp 108,000 / kg
This adjustment ensures the price reflects the actual weight the buyer receives after the production process is complete.
Why Should Garment Buyers Understand This?
Understanding gross vs. net weight provides several advantages:
More accurate material calculations: You can estimate material needs more precisely.
Avoiding misunderstandings with suppliers: Buyers understand that weight loss is a normal part of production.
Controlling production costs: COGS (Cost of Goods Sold) calculations become more realistic.
Assessing production quality: If shrinkage is excessive, it may indicate an unstable dyeing process.
Conclusion
In the textile industry:
Gross weight is the weight before dyeing.
Net weight is the weight after dyeing and finishing.
On cotton fabrics, weight loss is normal and usually ranges around 8%, reaching up to 10% for white. By understanding this, business owners can calculate their needs more accurately and build more transparent partnerships with suppliers.
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