How do I remove a dryer scratch off of black polyester material? It's a little white mark that runs across the black material, but the white and red is completely fine!
Can you use a permanent Sharpie to cover it?
This may not be a scratch but may be a thread that did not dye properly.
Use non-chlorine bleach and avoid fabric softener to help keep polyester shirts bright and white. This is a page about cleaning white polyester work shirts.