quilt backings
 

I have seen some king size blankets at thrift shops, wonder could they be used for backings?
Mother Tucker

I would think that blankets may be rather heavy to use as a backing and it may be difficult to quilt nicely. I guess it depends on what you are going to use your quilt for. If it is a simple pattern and will be tied that might be one thing. Personally I prefer to use cotton fabric for my backings.

If the quilt top is to be quilted, it may be better to use cotton rather than a blanket. Don't forget that batting will add to the thickness of the project, too. Perhaps you could try a little sample and see if the blanket will work for you? It also depends on what kind of blanket it is. If you are looking for extra warmth, could you consider flannel in place of a blanket?

I have seen old quilts use blankets as batting, but never backing.

The blanket could work for batting then use a sheet for backing.

well....it's YOUR quilt, give it a try and see if you like it...there is no right or wrong....but I would suggest you stick to a light weight blanket