I agree entirely with Henry Crawford's recommendations. Our collections consist of 17th century to early 19th century muskets, fowlers, rifles, pistols, blunderbusses, and a wall rifle or two. We apply labels to metal components and the usual spot is on the inside of the triggerguard bow. We apply the number using a base coat of 15% acryloid B-72 in toluene, then the number is applied with Gouache, and we top-coat with 15% acryloid B-67 in naptha (this allows you to remove the top-coat & number and leave the base coat intact). As with any substances which contains solvents take all safety precautions seriously! (ie., adequate ventilation; no sources of ignition; disposable gloves; use the smallest possible volumes; ask for, read, and understand the MSDS sheets) I would avoid stamping accession numbers into metal parts (a common practice in the not-too distant past) and I would avoid using sticky paper labels (I have spent numerous hours cleaning off the tarnish and corrosion products from these things). I believe that labeling has come up on the Museum-L list a number of times in the past year and I remember that someone posted information on a new high-tech system which could be tracked via a hand-held device. A system such as this might be adaptable and work quite nicely for an extensive firearms collection, particularly if security were of some concern. I know that I would be interested in hearing about these new systems from those who have had experience with them - perhaps someone could post the pertinent information to the List. Dave David Harvey Conservator of Metals & Arms Colonial Williamsburg Foundation P.O. Box 1776 Williamsburg, VA 23187-1776 USA voice: 804-220-7039 e-mail: [log in to unmask]