The only thing I really dislike about prewashing my quilting fabrics is all the strings that come loose during the wash, wrapping themselves in knots around the yardage.
The threads twist and pull at the fabric when they get tangled up in the wash--and you have to remove them before they go into the dryer so that fabrics come out wrinkle-free. Neglect to lose the threads and you'll see oodles of accordion pleats when you take fabrics out of the dryer.
It's easy to eliminate nearly all of the strings. Just clip off a little triangular section from each corner of fabrics before you wash them. Try about 1/2" or a little less. You'll still see a bit of fraying, but not enough to create bunches of knots.
Give it a try the next time you pre-wash your quilting fabrics--that little snip really makes a difference.