On the 6th day of Christmas my longarmer gave to me - the best advice - regarding backings.
If you invest all the money in the top of your quilt, please invest the same into backing fabric. Large sheets are not acceptable - at least not in my book.
Please do not select plaids, or stripes for backings. On the longarm, the backing stretches and skews in ways that are very unpredictable. I can never guarantee something will get centered 100% spot on. Sometimes before I even load the backing, the fabric is not printed straight, so that is another loss right off the bat - because most of the time I can't angle the fabric to become straight. Or the fabric is printed in a slightly wavy line ... even more fun! LOL You have probably experienced printed fabric being skewed if you have ever worked with border prints or panels.
Please piece with 1/2" seams. 1/4" seams could pull apart, or in my experience lately, the seams are less than 1/4" and the fabric is not getting sewn together - one side is slipping down when underneath the presser foot being sewn. 1/4" seams also do not lay as flat, even when pressed open on a backing compared to 1/2" seams.
Wide backings are a good thing!
Horizontal Seams are preferred.
I also love flannel as a backing too.
Here is something else I use daily ... Cheryl Ann's Design Wall:
*There is multiple links below for different sizes...
72" design wall:
https://www.amazon.com/gp/product/B004DGZ41C/ref=as_li_tl?ie=UTF8&tag=midnightquilt-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B004DGZ41C&linkId=751ff7f8004d9d194d799321b5208e12
54" design wall:
https://www.amazon.com/gp/product/B00FK9PKRO/ref=as_li_tl?ie=UTF8&tag=midnightquilt-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00FK9PKRO&linkId=ab60a0df5d6322e5e9412606c7502a3d
18" design wall / stand:
https://www.amazon.com/gp/product/B00G9I10F6/ref=as_li_tl?ie=UTF8&tag=midnightquilt-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00G9I10F6&linkId=2bd75c07245d00ff18b1c49703be7580
https://www.amazon.com/gp/product/B004DGZ41C/ref=as_li_tl?ie=UTF8&tag=midnightquilt-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B004DGZ41C&linkId=751ff7f8004d9d194d799321b5208e12
54" design wall:
https://www.amazon.com/gp/product/B00FK9PKRO/ref=as_li_tl?ie=UTF8&tag=midnightquilt-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00FK9PKRO&linkId=ab60a0df5d6322e5e9412606c7502a3d
18" design wall / stand:
https://www.amazon.com/gp/product/B00G9I10F6/ref=as_li_tl?ie=UTF8&tag=midnightquilt-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00G9I10F6&linkId=2bd75c07245d00ff18b1c49703be7580