Don’t use a tobacco humidor. There a couple reasons why, first, starting with the interior wood. Most tobacco humidors are lined with Spanish cedar, which has the potential to influence the taste of your cannabis. Cedar is primarily used in tobacco humidors because the oils in cedar transfer onto the cigars, enriching their flavor, but this isn’t necessarily a good thing for cannabis. The second reason why tobacco humidors aren’t necessarily a good idea is because most come with a sponge that’s used for humidity. Sponges that require propylene glycol can be unreliable when creating the appropriate water-vapor ratio. Any saturated sponge will wick all of its moisture until the entire sponge is dry in order to create equilibrium. This is standard physics, which is why people use chemicals like propylene glycol, to slow the evaporation. Ultimately, these methods can result in a over-saturating your cannabis. Therefore, if you do use a plain humidor, make sure its lined with mahogany, which is a very neutral wood that won’t impart any oils.