Why do people worry about the back being weaker because of seams when the front has about a zillion seams? I should think if seams are OK on the front, they would be OK on the back.

My oldest Daughter makes pieced backings all the time. The quilt never seem weak because of the seams, quilting would help secure the seams. Especially FMQ. Makes her quilts reversible.
I use larger pieces of backing fabrics, I'm too lazy to take the time to do the piecing.

I've pieced my backs for at least 20 years. The idea of buying separate backing fabric boggles my mind :)
The are usually much simpler than the front but not always

My quilts are always reversible. Some patched in blocks, some in designed sections, and some are the colors on the front in blocks or in rows. Depends on the quilt!

Well, thanks to all of your comments, I think I'm going to go for it! Mainly because I am tired of looking at these fabrics and want them used up!

Dunster - your quilt is absolutely stunning!! Thank you so much for sharing.

I like doing a pieced strip or two in my backings if I don't have a large enough piece to do the whole back. Sometimes parallel, sometimes not. Depends on my mood and the "mood" of the quilt. I guess I figure if I'm already putting seams in the backing I might as well make it interesting!

I did a OBW for my sister out of panels and I left one panel intact on the back so she could see the source and just put really wide borders around it. I think that is my favorite quilt to date, both front and back.

The only problem with pieced backs is for a long arm quilter. Too many seams piled on top of each other = a broken needle. Breaking a needle from this can result in down time to "retime" your needle to your bobbin" or could lead to the need for more costly repairs. If you are taking it to a long arm quilter and doing an edge to edge design I would IMHO suggest keeping it simple and pressing seams open.

The only problem or watch put is if the seams match front and back. Go slowly and carefully as the bulk may be too much for your machine.