I have already responded to Ms. Harritt directly, but since there has been further discussion on the subject, I wanted to repeat the information to the entire list.

Tyvek gets very soft if it is washed, so that could take care of the concerns that it is too stiff or sharp. The Costume Institute at the Metropolitan Museum of Art has been using the Tyvek labels extensively for 14 years. There have not been any problems with them so far. They do not, however, use a printer, but a Sharpie to write the information on them, so there hasn't been an issue with melting.

Maya Naunton
Polaire Weissman Fellow
The Costume Institute
Metropolitan Museum of Art