How humidity is kept constant in the Humicase.
Two rigid pods containing specially treated foam sponges mount on Velcro strips in custom recesses in the lid over the sound hole and behind the headstock. The sponges are to be soaked with the included special solution that activates the compound with which each sponge is impregnated during manufacture. The advantage to this special sponge is that it releases humidity into the air at a steady rate, keeping the humidity constant without increasing it beyond a desirable level. Just keep it in the case to monitor your humidity levels. When the humidity begins to drop, it's time to recharge the pods. After you've used all the activation solution, simply use distilled water to keep the humidifier pods charged and renew with activation solution periodically as needed to allow complete saturation of the pods.