I wanted to put a small pinecone/red flower print on green flannel on the back of my 2017 Christmas quilt. Wouldn't you know, I was 8" short?? I knew I'd need 5" more than two widths of fabric also. <sigh> So back to my well-loved red and green shirts. Here is a shot of the back after washing and drying. Flannel will shrink more than 100% cotton fabric, especially upcycled shirts that have been washed many, many times. For that reason, I always prewash my flannel backs. I have never had a problem with the seams raveling.
I started machine quilting a customer quilt tonight. I have done 3 passes. It is a huge quilt (95" x 108"), so I will be stitching on it when I can.
Here's my quilt back...
