I’m doing an art project that involves a lot of small photos mounted on foam core. Does anyone know about foam core’s longevity? Does the foam eventually morph into something else? Do the layers eventually separate? Does acid-free form core last longer than generic? And is there any reasonably-priced alternative that lasts longer, and that I can cut with a single-edge razor blade?
It usually warps and things come unglued, in my experience. I haven’t used it in a long time, so maybe there are better foamcore products on the market now.
I cover mine with clear contact paper and it lasts.
I made a base for a pet door out of a folding foam board presentation sheet. It lives in a window so one side gets wet when it rains. 6 months and still going strong.
PVC foam core should have a very long life. You can cut thinner material with a razor blade, maybe up to 1/4". The polystyrene foam core products benefit from additional layers of material laminated on them, or laminating several thinner layers of foam core product. One reason to use an overlay mask for a frame is to strength the material by doubling up around the edges.
Whether the layers will come apart and how brittle it becomes depends largely on exposure to changes in temperature and humidity.
The type of adhesive used to mount the photos also plays a role.
If it’s covered with an all-over adhesive the advantages of the acid-free board are diminished, so for this particular project I’d use the “regular”.
It’s hard to beat it for being light weight and maintaining rigidity, and ease of cutting.
I’ve got posters that have been mounted with dry-mount tissue to foamcore 20 years ago, and they’re still fine. Part of the longevity may be that the art has been in a frame for its entire life, but the material has certainly not spontaneously fallen apart.
Keep in mind that this is professional-grade board from a framing shop, rather than the “Elmer’s” brand sold at the grocery store for science fair projects. I have no experience with the “cheap” stuff.
I have seen unframed boards get funky on the edges, but that’s been more from handling than decomposition of the materials. If you’re dealing with unframed art for presentations, they’ll probably get grubby before the board itself goes to pieces.