I don't know how old this is. I know I don't remember seeing these fabrics and I am old so it has to be older than I am. The frayed edges are on the top and bottom and not the sides. My guess is that it is from the wear and tear of being used.
Quilt
[ATTACH=CONFIG]247988[/ATTACH]
Closer look
[ATTACH=CONFIG]247989[/ATTACH]
fraying
[ATTACH=CONFIG]247990[/ATTACH]