Quote Originally Posted by greybeard View Post
Incidentally, if you want to "condition" paper, there are various salts which, when in contact as both solid and saturated liquid, will maintain a constant humidity level until either the solid has dissolved in captured water or the liquid has given up its water to the environment. Much simpler and cheaper than a humidifier/dehumidifier setup with a control loop.
This is what I hope to do at some point in time. Modify an old forced air-print dryer to either maintain constant humidity, or with the addition of a bed of silica gel, to fully desiccate the tissue for storage prior to sensitization.

Here's a link describing various salts and humidity levels.