Surely all clothes are designer?
Has anyone ever made a jumper by accident?
"Aye, I was trying to make a kettle but you appear to be able to put your legs in it. And it's made of denim."
I can't help but think that the label 'Designer' is the lowest form of praise you can heap on an item, surely it just means: "This happened on purpose." Which is at best expected and at worse surprising for most designer clothing.