I use humidipaks in most of my guitar cases, especially because this time of year the humidistat in our living room measures 30 % RH, despite the use of a room humidifier. My Taylors, with their notable wood moisture content stabilization process, show no hardening up of the humidipaks, despite the fact the packs date to last spring! My new Froggy Bottom sucked the moisture out of its humidipaks in 3 weeks! Quelle surprise.