How critical is it that the back is larger than the top of the sandwich? I haven't pinned it together yet. My back is about an inch smaller than the top (on both sides, but the length is an inch longer). I was told I need to add more fabic to the back so it extends about 2 inches larger than the top because the quilting process gathers up the fabic. What's your opinion? Thanks for input.

It needs to be some bigger. If you are sending it to a Long Arm Quilter it will need to be several inches bigger. Ask you quilter how much larger he/she would need it to be.

Absolutely, if you are basting and quilting it yourself, you need a couple of inches on all 4 aides, which when you have finished quilting, you will trim off evenly with the top to prepare to bind it. A LA quilter will probably request at least 4 inches extra on all 4 sides. You should at least ad a strip to the sides that the backing is shorter than the front, as you will not be able to quilt to the edges-you will have to cut off part of the top to bind it. If you are not going to do allot of quilting (say, just quilt in the ditch or a simple block design) it won't be AS critical, but you still need at least a couple of inches of extra backing on all 4 sides. Be careful when layering your sandwich as well, that you get your top and batting CENTERED on the back, so you don't end up getting the whole thing basted, then discovering you had it a bit off-center and have a corner of the top that doesn't have batting or backing under it.

Your back does need to be larger than the front. I've tried cutting it too close and have always regreted it. Try adding a border all the way around your backing. That will frame it.

back has to be bigger... you have to allow for the quilting. how will you bind it the back will cover all the batting and top. you can take it off a whole lot better then you can put on after it is quilted. PUT IT on NOW. make it BIGGER you will be a put happer if you do it NOW.

Yes it needs to be bigger. You can add a strip of fabric to one end and then one side of the back.

If it is already 1" short on 2 sides, at this point you will lose 2" of your quilt top.
Chances are it will end up being more than 2" after you quilt. You may not be too pleased with how you will end up having to trim the top to make it match the backing :D:D:D

If you're going to add borders, I suggest you cut down what you have now for backing by at least few inches before adding additional fabric.

You don't want that seam anywhere near the actual edges of your quilt where your binding would go.

Or you could just add a piece on one side, say 8"-10" wide, shifting the whole thing over. Do the same thing for the length.
Don't even have to try to center it. That's probably the easiest.

Pieced backings are great. I do all mine that way.

Just keep that long seam a good way away from the parallel edges.

ok. thanks for help. guess I have to add some to the back. ugh.

My longarmer wants 5 inchs on each side.
I get by with a couple when quilting my self but I only make lap size.

Easy to fix, add a 5 inch strip all the way around. Should be big enough to send to a quilter or keep and do yourself. Back should be 3-5 inches larger on all sides so you have fudge room. Just when you think it's centered, you pull a little more here and a little less there and it doesn't measure up. Pretty soon, your short on one end. Better to add now and if your going to be quilting it yourself, start from the center to pin. Never cut it off until the quilting is done. Give's you more of that 'fudge' room. Good luck.

I agree with MTS. You don't want that seam right on the border.