Shrinkage and Fabric Growth Solutions for Sports Bras: Test Methods Explained
Testing is how shrinkage and fabric growth is verified for technical sports bras. Knowing what the numbers mean prevents unnecessary rejections.
Standard method used
The reference method is AATCC 135 dimensional change. It defines sample size, conditioning and measurement, so results are only comparable when the same revision is used. Because the underband and strap anchors carry repeated load, target checks are made on a worn sample rather than flat fabric alone.
Reading the results
Aim for under 3% in length and 4% in width after five washes. Values near the limit usually indicate a borderline recipe rather than an acceptable one. Keep AATCC 135 dimensional change named in the tech pack so every lot is measured the same way.
Typical limits in buying specifications
Brands set different limits depending on the end use of the technical sports bras, which is why the target must appear on the tech pack before sampling. Where technical sports bras is worn for everything from yoga to high impact training, set tolerances around that range of movement.
Common testing mistakes
Testing unwashed fabric, mixing shade results, and skipping conditioning are the errors that produce misleading numbers. Any change to power mesh and bonded spacer panels requires re-testing against under 3% in length and 4% in width after five washes before bulk is released.
Records to keep
Keep every report with the bulk file. Repeat orders are released faster when the previous result set is available immediately. Past reports from AATCC 135 dimensional change help the mill reproduce the same recipe on the next order.
