If your case has room for a coin, then it has room for some
type of label, even if that label is nothing more than a number cross-referencing to a list. For my trays, I designed small, 1×2 inch tags which I print on acid free paper and fold in half to net a 1x1 inch tag. The front-half has a numeric
collection i.d. (which cross-references to my detailed
collection database) and very basic information -
denomination,
weight,
mint and
standard catalog references. The back-half has
provenance information. If you use tiny fonts, with a modern printer, you'd be amazed how much you can fit into a 1x1 square tag.