each of my backs are as thought out as the tops. i choose the backing for each quilt individually= i never use solids, always some sort of print or batik. i try to get wide fabrics but at times piece the back-sometimes the quilt is 2 quilts put together- both sides a pieced top that goes together.
a solid will show ever stitch in the quilting- prints tend to be a bit more forgiving- but regardless- the backing goes with the top either by contrast or by matching.

Mee, too. And if possible, I like busy little prints. They cover even more of my bad quilting!