How do you keep the front opening corners of a sheet from folding in?
This only seems to happen with my mare's sheets, not the heavier lined blankets. The corners of the sheet just above the front buckles seem to want to fold in and rub. The sheets fit her well otherwise, I think it's because there is no fill and the blanket is therefore thinner and more 'bendy'. This is more annoying to me than to her !
I've have a few different brands over the years, Weatherbetta, Horseware, etc. They all seem to do this. She's out most of the time and likes to yahoo around, although she is not hard on her blankets.
I don't know if relates to your problem, but what helped me (when the fly sheet was doing that when I had it hooked on the second "d ring clip") was to thread the top snap through the first d ring before clipping to the second. Folding in stopped...
I have the exact same problem with my TB mare - her Amigo medium weight stable blanket started doing this only on the left side and rubbed all the hair off one point of the shoulder.
I found when the velcro was new and really sticky it didn't seem to do it as much, so you could try replacing the velcro. I just gave up and put a Bossy Bib on her so it wouldn't rub. The blanket actually stopped folding over once I threaded the buckle through the strap on the front of the bib.
I've spent most of my life riding horses. The rest I've just wasted.
I was actually thinking of removing some of the rip-stop lining from one of her trashed blankets (I keep them for 'parts' for repairs LOL) and hand-tacking it in around the neck - maybe doubling it for additional thickness ?
The sheet she on now is the Horseware one with the t-buckles across the chest, so they're not adjustable. Really love this sheet, it has kept its waterproofing through several washes and is wearing really well.