What do blanket rubs actually look like?

I've only ever seen rubs the shoulders and the top of the withers. Ricci's blanket rubs the top of her withers. However, I think it's entirely possible for the blanket to be rubbing on her hips. The hips move, creating friction, which is when the rubbing occurs.

I've always been told the hair only has a chance of regrowing in white if the follicle is damaged. That would require a blanket rub so severe the shoulder bleeds or is raw. 99% of the time it's just rubbed off/broken hairs.

My friend's horse got really bad rug burn that it cut through the skin. I think the lycra protector tore off... So yeah, she know has white hair permanently there. Just don't let it get that bad!

The hair doesnt turn white but it grows back white if the skin has been traumered

Mine has a white spot and never was raw or damaged before. Just showed up.
Also if you have a breed of horse that is not to have white on it's body the rules state the exception for white from blanket rubs.
Some of my blabk horses have turned white where it looks like another horse may have bit them.