homebody323

For years I have tried to explain to my quilting customers that they should piece the backs for their quilts as if the fabric had a definite up and down pattern. When they don't the fabric will sag on one side when loaded on my quilting machine while the other side is perfectly straight. Further down the back the sag and straight change places. I'm sure this has something to do with the weave of fabric or something but I don't know exactly why. If anyone knows, I would be so happy to be able to explain it to my customers and then maybe they will do it the correct way if they understand why.

bearisgray

In many cases, the crosswise threads of a fabric have more stretch/give than the lengthwise threads of a fabric.

To check this out:

Take several pieces of different fabrics -

Measure out a ten-inch span (no need to cut it) - now pull it as much as you can - see how much it stretched - measure it to verify the number.
Now measure ten inches the other direction of the same fabric - stretch it and measure it.
Was there a difference?

(For good measure - you could also check how much stretch there is on the true bias of the piece.)

This is usually very obvious with one-way stretch knits.

elnan

Not a prolific quilter, but do know that cross grain stretches more than straight of grain.

Pagzz

I think every piece added to a pieced back needs to be squared before adding to the back. if you fold up a chunk of fabric that looks like a rectangle or square and it doesn't match evenly when folded then that extra fabric is going to affect the sag etc. unless you trim and square it.

Geri B

Three things here...1.yes fab does have a "stretchy" side....WOF will give more than LOF...that's why many patterns/teachers/designers suggest cutting borders from LOF...less chance of wavy borders......

2. If when the selvage edge is not cut,ripped, from backing fab, when joined together that seam is very tight and can cause sag when putting on frame, and worse, when that quilt is washed can pucker that seam.....if one of my clients brings in a back that has seamed back with selvage edge still on, if I can, without destroying the integrity of that seam, I will strip it off, if not I will make small cuts into it at intervals just to release some of that tautness.

3. When I put a quilt on the frame I will make sure it is mounted with those seams going horizontal...if it's a patchwork back....there seems to be no problem as it moves pretty much as does the top.

On a few rare occasions I have had a saggy bottom no matter what, so in that case rather than drive myself nuts as I advance the quilt sandwich, I have found by putting some chunks of wadded up batting against the roller from the underside will take up that sag on the sandwich as I stitch it, then remove those "chunks" and proceed on......just what I do......

ManiacQuilter2

I have quilted on my Bernina for over two decades and I have never noticed a problem. Yes, one direction is a bit more stretchy than the other. Fabric is getting more expensive so I always try to get the most out of what fabric I have for backing.

Geri B

I think the problem of sagging is aimed more at longarm quilting, not using DM or in process of moving quilt rather than moving machine. Putting the layers onto rollers then stitching would be where the sagging would be more apparent, because of the degree or lack of tautness put on each layer.....

feline fanatic

Yes it is strictly an issue for quilting on a rack or frame. Not necessarily LA, any rack set up, even those for hand quilting or racks with a domestic. I have found that if the back has one side saggy when loading on my frame I simply roll it back and forth a few times and that always solves the problem for me. I do this before loading on my batting and the top.

Melanie Rudy

I have never had a problem with this. I always remove all selvages when I put the backing fabrics together, whether it is 2 pieces or many.

kristakz

I always (or as much as possible) load my quilt back with the seam running across, not vertical. Vertical loading with a center seam is just asking for trouble in my experience. But as for the sagging, I think it has to do with how you load the quilt, not how the customer sews it (although I can't explain why it would be better in the other case). But maybe it's a case of things not being completely square? Try to picture loading a slightly wonky rectangle onto your frame. The side that is "longer" at the top is going to sag initially. Then, when you get near the bottom, the other side is now "longer" and will have extra fabric to sag.