Oh! Ahhhhhhh, how pretty. Pinkypig. Your blocks and your muslin look fantastic. forgot to mention your hand quilting. Wow!!! That looks outrageous, too. Good job.
Like others, I have used lots of muslin to back quilts. The muslin makes for a soft, soft quilt that is perfect for baby and little kids quilts. I also use the muslin for the charity quilts we make for foster kids and for our local Veteran's Hospital.