I have a pair of floaty chiffon-ish material black trousers (no label so not 100% sure on material but very thin) and in my haste to get a train I tripped and grazed the knee on concrete. The material didn't tear but it grazed and I'm not sure if I can fix it! I've attached a photo if anyone has any suggestions, I've not been able to find anything online. They were only off eBay but I'd rather not have to throw them out if I can save them!