ElizABETH,
I have been to several quilt shops that rip their fabrics. Quilt shop quality fabric rips well. I know the stuff in my stash from Walmart or Joanns doesn't perform as well. The comment about the crossgrain is true. One of the first things I was told in Junior High Home Economics 40 years ago, was that the fabric is often rolled on the bolts under pressure and possibly even damp. It is often distored in that direction. They also told us not to purchase fabric that was printed off grain. Those of you who have come to quilting without first garmet sewing need to take grain into account. Sewing patterns are marked for grain for a very good reason. The same principles that make a garmet hang properly apply to quilting. Those of you who have had a quilt end up having ruffled borders learned the hard way.