pat macaluso wrote:
If your looking for vaper barrier, I produced a few rosewood guitars for extreme climate swings and used epoxy on the inside of the back and sides. It was sanded to a satin. Not super great looking, but did the trick. Nitro on the outside. I can't say technically why it worked, but maybe some of you chemEs can.
I don't know enough about chemistry or physics to comment but the phrase "zircon encrusted tweezer" did come to mind

Cool idea!
Related is Rick Turner who was Jerry Garcia's on the road tech for a long time (and survived...

) and who is a friend of ours and minces no words.... built a guitar that went to Antarctica and also survived. It would be interesting to know what he did about RH shifts.