I thought I would try something different with the yellow/gray quilt. Since it is 48x48" finished, it is wider than a standard width of fabric. I usually just handle that by cutting a strip the required width (plus the extra required for layering and quilting take-up) and sew it on. This time, I decided to watch the free Craftsy class called "Creative Quilt Backs" or something like that. So even though I'm not much of a modern quilter, I learned some things that I will share.
I decided to slash and tear the backing off-center and insert a pieced strip. The teacher advised not to insert a strip down the center, because it's hard to line up centers while layering, and they could shift while quilting. Then your eyes notice the differences!
I cut two strips 4 1/2 by WOF for yellow and pieced them together. Then I cut a few strips of the dark gray 4 1/2" wide. I had to piece a bunch of strips together of the grey because I only had fat quarters for that color. Then I strip-pieced the yellow and gray strips together, cut them at 4 1/2" wide across the strip unit and made four-patch units. Then I pieced the four-patch units in a strip 8 1/2" wide until I had my desired length of about 52".
By the way, I'm pressing all seams open to reduce bulk on the backing!
Next, I learned from the Craftsy class, that to piece your strip into the two backing pieces, mark all the centers of the strips, then pin together at the centers, then pin working your way out to the ends. Don't just add strips and line them up from the top or bottom! Working from the centers out gives a more uniform, centered quilt back, and if your layers shift at all during quilting, then they won't slide off an end that's too short and not have enough backing. Wow. I wouldn't have thought of that, but it makes sense!
Learning and trying new things is a huge part of why I love to quilt. There's always something new to learn or try, and I like to challenge myself just a little with each project. That way, I'm always growing!