Ronald and Susan, I agree with your suggestions re: enclosures. I think that to give more protection and surface for labels and accession numbers (or additional information) is better to use boxes rather than to write on the artifact itself. You can write with pencil, pen, or sharpie. You can always change the box and rewrite the information, if it is necessary. Also, for ambrotypes and many photographic processes the idea of “box inside box inside box” is the best to protect the objects against grime, dirt, pollutants, light exposure, T & RH fluctuations and direct handling. The more barriers you have from ambient environment the better, but this option can be both expensive and time consuming. It also depend in the value of the material and how often is used and/or handled.