The only saving grace is that *usually* when you have a thread mess under the quilt, it's easy to remove because the stitches aren't well formed. And knowing WHY you have the mess is good, because it's easy to fix. I find that I've become complacent lately and haven't been checking the bottom of the quilt as often as I should. A door mirror underneath wouldn't help me - I'd probably step on it and break it, and anyway I like to crawl under there and hide and stare at my stitching to see how the pattern is looking on the back.