Colour Bleeding Solutions for Running Shorts: Common Failure Causes and Fixes
Below are the failure patterns most often seen when colour bleeding affects running shorts, with the correction for each.
Failure: hidden until worn
colour transfer into wash liquor or onto adjacent panels usually appears after several sessions. Because it develops slowly, it reaches the customer instead of the inspection table. Because high cadence movement plus perspiration at the waistband, target checks are made on a worn sample rather than flat fabric alone.
Cause one
hydrolysed reactive dye not fully washed off. Keep ISO 105-C06 washing fastness named in the tech pack so every lot is measured the same way.
Cause two
overloaded dyebath. Where running shorts is worn for road, trail and track training, set tolerances around that range of movement.
Cause three
insufficient soaping. Any change to lightweight woven or knit body with a knit liner requires re-testing against grade 4-5 colour change and staining before bulk is released.
Correction and prevention
Apply increase soaping at 90 degrees first, then verify against grade 4-5 colour change and staining using ISO 105-C06 washing fastness. Lock the corrected settings into the bulk recipe so repeat orders behave identically. Past reports from ISO 105-C06 washing fastness help the mill reproduce the same recipe on the next order.
