I have two acoustic guitars left. These were the ones I could not bear to be without.
So I'm inclined to pamper them. I read this thread with interest, and will tell you my
experience with humidity change and guitar dynamics.
When my Cindy was diagnosed with a brain tumor in 2019, I retired from my photo
business and from touring with Mustards Retreat. I sold all my "vintage" instruments
because I thought we might need money as her treatment proceeded. I reduced my
collection of instruments from 11 to five.

These I kept with me as we traveled to Tucson AZ, and stayed there during the course of Cindy's Cancer.
They were necessary for my morale. The electrics did not suffer from the change in climate, altitude or
humidity. They are pretty well sealed with varnish, and I had no trouble with them.
The acoustics are different from one another. The Martin is an XC1T, considered to be one of Martin's
'bargain" guitars and equipped with back and sides made of High Pressure Laminate (HPL)
whatever that is. Spruce top. Its neck is made of "Stratabond" which means it is laminated like a butcher block
except with thin strips, maybe 1mm thick. In spite of its dubious & non traditional construction, that Martin
is a brilliant guitar, with excellent tone and a fine pickup system. The Stratabond neck is very stable tuning wise,
and the HPL back and sides give plenty of resonance and tone. In addition, these materials are much less affected
by changes in temperature, humidity and altitude than any other guitar I have owned.
Pretty cool. I had no trouble with the Martin, and she kept my spirits up, which I needed badly.
I did NOT de-tune that guitar, but I am in the habit of using alternate tunings, so she went up and down
from DADF#AD to standard, and EBEAbBE and back to standard etc etc... The Martin gave great service
and no wood issues. No proud frets, no belly, no cracks.
The Gibson is my 2018 J-45 AG, which was my consolation prize for selling so many prized instruments.
It's also an innovative instrument, with back and sides made of walnut, maple neck, walnut bridge and fretboard.
The top is good spruce, and the bracing underneath is traditional Gibson construction... the J-45 design has
been around for decades. My experience with the Gibson has been that she is much more affected by drying
out. If I leave her on the stand too long, her neck will back-bow and she developed a belly. I've had her set up
three times since buying her. Each time she needed some humidification by the luthiers, each of whom has a
special way of re-humidifying peoples' guitars. For the Luthiers, it's routine work. Setup has been able to return
my Gibson to playable condition. And I've learned not to leave her out on a stand in the Arizona dryness, or in the
Michigan Winter dryness. Hard for me, because when I like a guitar a lot, I like to have her out on a stand
where I can gaze affectionately at her, or just pick her up and tune up and play.
The lesson learned is that drying out can really do a number on an acoustic guitar, and so can over-hydrating.
My lovely Gibson went from back bowed to action way high, because I brought her out of Arizona this autumn,
and stored her in my sister's damp basement while I sorted out my new life and found a place to be. Setup was
expensive but worth it. When that guitar is in fighting trim, she's a joy to play. When she's unhappy, she can
be impossible. Vigilance and TLC is the ticket. She doesn't need to be detuned... although she sounds really
good tuned a half step low. I named her Zelda.
