Sure, why not? I use muslin a lot. I've used great wide muslin for quilt backings too. Muslin is a great fabric, it becomes softer and softer with use, laundering and holds up well. I have quilts from the very early 1900's with muslin backs that are lovely, soft and wonderful. I don't know why you would be leery of using muslin. I use it for backgrounds for appliquéd blocks and embroidered blocks too. Muslin is a basic, staple fabric. ( like many fabrics there are different qualities of muslin. There is very thin, cheap muslin and there is very nice, quality muslin. )