I have all my prints hanging for me to judge for exhibition in my home, unglazed.
Mounted onto a Diabond style substrate.
Four different brands and Lustre to matt papers printed by me. Some have OBA, not something I like but try avoiding it.
It is a large high ceiling space in Dorset half a mile from the sea.
Oldest prints mounted this way, about 20 months or so.
The prints are perfect, just like the day I mounted them. The prints with OBA's printed and only hanging for six months so far.
I intend to exhibit them like this as I prefer the look and so do most of my visitors so far.
Transport is an issue as they are prone to damage, so may box frame them to protect the edges.
Foam and framed prints and canvas stretch mounted prints in the same environment had some failures with warping.
I don't spray or coat anything or avoid direct lighting. Well, there is not much of that in the UK anyway.
I know this is not a long time for judging longevity but it is an alternative to bulky, costly framing with an optically clear glass, the only alternative for me as all other glass I have tried very obviously showed colour shifts when looking at the art work. Just to expensive and laminates hot or cold available here are not archival so why bother.
If I bought a sculpture I would not want to knock it over, so why would I spill handle or whatever a hanging picture?
It also nice for people to see the paper if you have been selective in the printing process.........................!