These masks are of very good quality, and the fact that the material stretches makes for a good mask fit. However, once they have been washed, it seems that they have shrunk slightly, so they don't fit quite as well. I washed them in cold water and hung them up to dry. They still are quite usable once washed, but they tend to slip down off the nose when you speak, and do not go quite as far down over the chin. Overall, they are a very comfortable mask.See full review