If cost is a factor. I'd strongly suggest a patterned sheet. I use them all the time on my quilts and you often can get them in 100% cotton or cotton rich 60/40 or even 80/20 blends. Quite often a small local department store near my home has name brand sheets that are seconds for less than $10. I stock up when they are on sale and shop my sheet stash when I need a back. I try to buy King size or at least Queen size flats so I have plenty to work with. The other advantage of sheets is that there is no seam. They machine quilt beautifully and wash and wear well.