I have a friend who wanted 11 yds of fabric for backing a very , large quilt. The fabric she wanted had flaws in it. Some were in good places (where she would cut to piece it) and others where she'd have 1/3 yd she'd have to cut out or so. Anyway, she really wanted that fabric, and there were enough good lengths in it if she bought the whole 18 yds, so she did. She does quite a bit of quilting, so the little extra pieces were welcomed.