Originally Posted by quiltingcandy
It sounds like when you added the border you measured the edge of the quilt and not the center. For some reason, the border will be too big and you will get waves in it.
That's my thought, as well. If the edges of the quilt are larger than the measurement you get when you measure through the center of the quilt, the edges will wave, or, if you hang it, it will not lay flat.