Prewashing quilt top, 12" squares and fleece?
 

I don't usually prewash my fabrics because I usually quilt very heavily and this helps prevent shrinkage. There are three cases I need to prewash.
1. I'm making throws that are going to be backed by fleece (fleece doesn't shrink). Can I prewash the entire quilt top and not do the individual fabrics before I start piecing.
2.Do I need to prewash the fleece?
3. I'm interested in joining some swaps. The last one I did all my fabric was prewashed but future ones this may not be the case. Can I make up a squares a little bigger than the required amount and then prewash them after I've pieced them? Then I can cut them to the correct size. Will this work?

Thanks, Mary Jo

1. No!! If you are going to prewash, wash the whole pieces of cloth before cutting. If you wash the top after piecing, it will ravel like crazy. Just think of all those raw edges!

2. Sorry don't have an answer for this one.

3. Many people use unwashed and prewashed fabrics in the same top and have success. If you are in a swap, unless it is specifically stated to use one or the other, make your block to the correct size and send it off. Making the block larger and washing will have the same raveling problems and I cannot see how you could cut it to the correct size later.

I would never prewash a quilt top!
Also, there are lots of folks who do not pre-wash anything and back their quilts with non-shrinking fabric (sheets come to mind), and have no issues.
I back most of my quilts with flannel; and although I pre-wash the flannel prior to adding to the quilt, it still shrinks at a different rate than the regular cotton front, but there is never an issue or concern.
Once the quilt is quilted there shouldn't be an issue.

Some fleece does dhrink.

I usually do not prewash, but yesterday OPENED my eyes. I am starting a quilt that has adhesive in it for applique (usually hand applique, but no time this time) so I hand washed my fabric. So glad I separated the colors! The red bled so bad. The blue also bled a little. New fabric, fresh off the bolt, from an LQS. Had I used that fabric without prewash, the quilt would not be fit to gift! Since the "new" process of dyes, etc. I thought that the only reason to prewash was for shrinkage, therefore, rarely prewashed. I am now a believer!!

I am a pre-washer, but if you want to pre-wash the quilt, just fold it in half with all the seams in the inside, then tack it together with a basting stitch, wash on gentle. I would line dry it but I believe you could dry it with a couple of sheets.
My daughter wanted me to replace the batting in the Christmas quilt I made over 20 years ago, and I did the washing routine to see how the holes where the ties would react.

I washed a top once when it fell out of the bag into a mud puddle. Washing was really the only option! It did ravel a bit, but I was still able to finish it. I usually pre-wash for both shrinkage and color fastness, learned log ago that a lot of fabrics bleed.