It's not the UFO I was aiming for originally, but every UFO finish is a good finish. I finally succeeded in matching up my new backing with an old UFO. It is now quilted, bound, and ready for use.
The front of this quilt is a UFO I've had sitting around since Feb 2014, so it was a full 4 years in the making. After my last post, I finished adding strips to 2 sides of the quilt to make it square, and adding 2 borders to it. A quick test drive and it looks like a perfect fit. The yellow border should align closely with the outer sashing of the green quilt.
One reason this quilt top has been a UFO for so long was trying to figure out how to quilt it. I had visions of custom quilting, but could never settle on a design I liked. The advantage of making it 2-sided - custom quilting is now out of the picture, because that would never look right on both sides.
I picked a nice pantograph (spiral bubbles) and quilted it up over a couple of days (it's a BIG quilt, and that pantograph is denser than I realized). All done now, complete with 2-sided binding.