One more reason to wash fabrics before using!
Another solution is to put a loose-winged butterfly or dragonfly over a small flaw. Even though I always wash before hand, I finished a quilt for Japan and when making my last inspection for thread ends (post finished laundrying) I found a small flaw... a hole. I quickly made a two sided butterfly (both back and front) and tacked down the body right over the hole. Actually, I've done it for that reason more than once. :)