Tearing 4 sides of fabric. Square?
 

I have yardage 108” x 108” I would like it to measure 80x80”. I have ripped the 2 sides vertical from the salvages. If I tear the 2 salvage sides, will my fabric automatically be square?? This is for a quilt backing. Thanks!

I would leave it the size it is if you are taking it to a long armer for quilting. You need extra fabric all the way around to put it on the machine. Yes it would tear square but I would not advise doing it. until you see how your quilted wants it done.

physically square, probably not, as most fabric gets stretched a bit off grain in the manufacturing and rolling process. However it will be straight of grain and that is what I go for. I always prewash my backing and find that helps a lot in relaxing the weave and getting to close to straight.

It does depend on what you LAer wants. I like to go not more than 10" bigger on the side I'm going to mount (usually the top, but sometimes I go sideways) and then I leave the length what ever it is and trim that off afterwards. I don't like having a lot of extra on a side when I'm advancing the quilt as it does not have batting so does not roll up the same. When I have that, I'll pin in a tuck occasionally as I roll to take up the slack.

Sometimes fabric doesn’t rip straight down like you think. I’ve made the discovery the hard way—where the rip is supposed to travel due south from Nebraska to Kansas but decides it wants to see Vegas on the way.

In my youth, you could comfortably rip fabric on the WOF and have a straight edge. Now, not so much. A lot of the fabric is woven "funny". And when I have seen someone rip fabric recently, you have at least 1/4" to 1/2" that is not usable due to stretching and raveling. I have never tried to rip down the selvedge. I didn't even know that people did that. Your long armer is not going to want any extra ravels or stretchiness. Consult her before you do anything with the backing.

The fabric usually gets "wonky" during whatever is done to it after it has been woven.

Tearing fabric is traumatizing to it.

Even if all sides measure 80" it does not mean it is square. Lay the fabric out and place the large square ruler in the corner as a check. Utube has lots of videos. Hope this helps.

Hahaha. So true and well said!!

You may have to "stretch" it square.

Measuring from opposite corner to opposite corner, then doing the same with the other two opposite corners, will give you the same measurements if the piece is square. But then... is your top perfectly square?

I let 'square' be an illusion, rather than necessarily actual. If it looks square, it's square.