moving out to college and leaving a couple electrics at home. they're going to be undisturbed for a few months at the very least, and likely longer. what do i need to do to ensure they're not damaged at all by the lack-of-use? i assume i should loosen the strings as well as make sure they're not stored in a humid/overly hot/cold place.
i would'nt bother loosening the strings in a few months of not being toutched they will go all dodgey anyway!
I would give them a good cleaning too and make sure they're stored in hardshell cases if possible. If you can, keep them out of basements (too cool and damp) Attics, or garages. By maintaining a relatively constant temp around them you'll lessen the chances of any damage. BTW, since you'll probably loosen the strings the neck relief will change due to the reduced tension. Hopefully when you retension them on your return the neck will come back OK without any adjustment (it may take longer to react due to the time the neck will be left in the untensioned state).
Moving on.....
what could be the damaging effects of storing a guitar in a hard shell for 5 years. did not loosen strings to my knowledge. never opened in that time
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I had a strat put away in a soft case for almost 9 years tuned to full tension. I had stopped playing for a long time but didnt get rid of it. Never worried about humidity or temp. Pulled it out and it was maybe a half step down out of tune.