My MIL taught me to bind quilts using the backing fabric and some of the quilts at the farm are over 100 years old and were made by her grandmother. The binding on them are very worn but so is the rest of the quilt. If it is a special quilt, I make a separate binding. If it is a use it every day quilt, I often self bind it using the backing fabric. These types of quilts will not be heirlooms and will literally be worn and washed to shreds. I figure the self binding will last as long as the rest of the quilt.