Can anybody give me some advice on the type of foam that I can safely use as backing on a coin display I'm currently building? A foam that will be in direct with the coin's surface and won't break down into components that may damage the surface of the coins. The coins in question will be bronze and silver specimens.
I can give you an example of safe foam, - the same stuff used in Coin World coin holders and Air-Tite coin holders, it's completely inert. Problem is, I doubt you'll be able to find it in the form you want, like sheets of it, at least not unless you can track down the company that makes the stuff for them. And if you're trying to build a display case, well, everything you use to make the display needs to be an inert material, the backing, the frame, everything. That means no wood, no regular paper, no regular cardboard etc etc. And that's only part of the problem with displays. The other part of the problem is that displays expose the coins to all the things you really should protect the coins from - primarily the air itself - and everything found in it, especially moisture, but other contaminants as well. And yeah, I understand the allure of displays. But all the problems that go along with displays pretty much make them a bad idea - for the coins anyway. Because those coins you're trying to display because you like them and are proud of them, well they probably won't look so good given some time.
Why not? Very much depends on the specific plastic foam being used and whether it's inert or not. Food grade plastic foam should be fine. Well put! I think that's the most common answer as it reduces most of the problems down to "are Air-Tites really air tight"?
I know somebody used a CAPS album page and placed it in a frame that could swivel at the bottom as a display. CAPS system uses Air-Tite brand capsules. Here's what a CAPS Album page looks like (it's in an album, though).
