Age lines?
Moderators: rickenbrother, ajish4
Wood can really expand/contract due to extremes in humidity, whether it is in the case or not, but the finish does not, hence the cracks. I know Taylor is extremely zealous in recommending a guitar's environment humidity stay between 45-55% (see their website for app notes). Dry winter air will eventually affect a guitar in its case, unless a Dampit or similar is used. If TOO MUCH humidity is the present, you might end up with mushrooms in the soundhole. Maybe you could use those those camera dessicant packs, changed regularly.
