I will use acrapes of material for my backing eaither from the project I am working on or material from my stach that will work. I also will use sheets, they make great backings and are cheaper in many cases for backing. I know the wuilt stores will always not to do this, but do not forget they are in the business of selling material. As a long armer I will tell my customers that if they do have a peiced backing I cannot always guarntee that it will be perfectly sq. I love have a story on the back of my quilts as well as on the front.

i almost always use the scraps from the quilt i made into the backing either using over sized blocks or just piecing them together with other fabrics if needed

The yardage requirements for the lap-size quilt I'm working on now weren't clear at all and I purchased way too much fabric. I took advantage of my mistake and made a D9P for the backing. I've almost finished FMQ it and haven't had any problems at all.

Have made alot of pieced backings using large pieced blocks either
in a row down center of backing, or randomly placed. (If in center the
quilter will have no problem "centering"). Good way to use up your stash,
and have a reversible quilt, more or less.

I've done a couple of different things. On one log cabin, I made the backing one giant log cabin block. When I have leftover blocks (or material to make a few more) from the quilt top, I make a strip of those (either horizontal or vertical) to connect two smaller widths of fabric together. I have even taken odd-sized leftovers and just pieced until I had a large enough piece for backing. I buy wide backing, but only when its a deal too good to pass up.

Squaring your backing, pressing seams open & starching it heavily will help a pieced backing tremendously. Keeping it taut but not tight on the frame will keep it from skewing.

I have more trouble with dirty batting than pieced backings on my frame. Make sure there are no selvages left on the backing in the area to be quilted. I've left them on before and my needle did not like them one bit--too dense.

I almost always piece my backs. I try to make it so that the back doesn't have to line up with anything on front. I haven't had a problem going over the seams, either with my DSM or my longarm.

Here are two of my more intricately pieced backs; both have log cabins on the front. The first was quilted in sections on my DSM and the 2nd on my longarm.
http://www.quiltingboard.com/t-23612-1.htm
http://www.quiltingboard.com/t-82165-1.htm

And here's one that's not so intricately pieced:
http://www.quiltingboard.com/t-22410-1.htm

Beautiful quilts as usual. I really like your pieced backings. Thanks for sharing.

Me too, always bought from SA or Goodwill
David

Some go for simple backs, some look like another quilt top. It all depends on what you like. If you hand quilt, you may want to consider how many seams you want to quilt through though :D:D:D