Originally Posted by bj
Some shops tear, most cut. With tearing you do get a truer straight grain across the end. Most of the time, when I get home with "cut" fabric, I lose some on the end from having to square it up. So I'm not sure, in the long run, if it matters whether you lose it from "squaring" or from "neatening" the end.
Most fabrics tend to twist when being rolled onto the bolts at the manufacturer, and can be off by as much as 4-6 inches at the beginning of a brand new bolt. Many untrained staff at some of the fabric stores don't know of this, and just cut without evening up the fabric first. Ripping of wovens is actually more accurate. I was trained to only cut true woven plaids such as ginghams, and then a single layer at a time. Does it matter? If you are putting on a pair of pants (chinos) that have not been cut on a true straight grain, they will pull in the seat with every step you take. On a quilt of small pieces it may not be as important.