Oh, dear. It's a mess!
I've finished my quilt top with 3 borders and basted it together. Then I discovered that the borders do not lie flat. They matched up beautifully while sewing them on, but there is no way to "quilt that out!" The corners are mitered, so putting them back together after unsewing and correcting is daunting. The quilt is nearly king sized, so I had no surface large enough to see the extra bulk. I guess the weight of the quilt pulled it flat. Any ideas on correcting those mitered corners now that they have been trimmed?