Colour Bleeding Solutions for Swimwear: Test Methods Explained
Testing is how colour bleeding is verified for swimwear. Knowing what the numbers mean prevents unnecessary rejections.
Standard method used
The reference method is ISO 105-C06 washing fastness. It defines sample size, conditioning and measurement, so results are only comparable when the same revision is used. Because the fabric stays wet, stretched and chemically exposed for hours, target checks are made on a worn sample rather than flat fabric alone.
Reading the results
Aim for grade 4-5 colour change and staining. Values near the limit usually indicate a borderline recipe rather than an acceptable one. Keep ISO 105-C06 washing fastness 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 swimwear, which is why the target must appear on the tech pack before sampling. Where swimwear is worn for pool training and beach use, 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 nylon and polyester knits at 190-230 GSM with high elastane requires re-testing against grade 4-5 colour change and staining 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 ISO 105-C06 washing fastness help the mill reproduce the same recipe on the next order.
