How does Boveda work? It’s all science. Mix certain salts with water and together they naturally regulate humidity. Boveda’s patented packaging allows the cleanest, most-purified water vapor to either be emitted or absorbed. Boveda acts on the environment around it. By adding and absorbing moisture, Boveda keeps the contents of a sealed container at a precise relative humidity (RH) level. Cool, huh? The number printed on Boveda are the RH%. Whatever product you’re storing calls for specific RH levels.