So Sponge products consist of a chemically neutral mineral material, organized on several size scales:
The space between the nanocrystals constitutes the active porosity for the adsorption of water vapor.
Pore size defines at what humidity level the material starts to adsorb.
The So Sponge material starts to work when the humidity level exceeds 60%, which is slightly above the recommended level for ambient air.
By modulating the size of the pores, one can choose to favor intermediate humidity levels (between 60 and 80%) or very high humidity levels (> 80%).