Tearing fabric to obtain straight of grain?
I am not a fan of tearing fabric for straight of grain when quilting, but I do have a question on how it should be done properly.
I was recently at a quilt shop I had patronized many times previously where they cut the fabric with a rotary cutter. This most recent visit, the staff member measured the fabric, placed her finger at the correct mark, snipped the fabric (on the fold) and proceeded to tear it to the selvedge edges, gripping both layers of fabric at the same time.
She was so quick, and I was so surprised, as previously this store cut the fabric. I do not like to buy fabric where it is torn. (Personal preference of mine)
Subsequent to this, when I went to use the fabric, I had nothing but trouble - ripples, shifting when trying to cut/pin etc and it didn't seem to lay flat as easily as usual.
When you plan to rip fabric, I was under the impression that one snipped the selvedge, tore to the opposite side and then cut that selvedge.
What is the correct way to do it? My most recent experience seemed to be really detrimental to the fabric.