A humidor is any kind of box or room with constant humidity that is used to store cigars, cigarettes, or pipe tobacco. For private use, small wooden boxes holding a few dozen cigars are common, while cigar shops may have walk-in humidors. Humidors can be used to maintain consistent humidity level for other goods; the Colorado Rockies Major League Baseball team stores game balls in a large humidor at their home stadium, Coors Field, to counteract the effects of Denver's low humidity. Many humidors use hygrometers to monitor their humidity levels.
Walk-in
Most common in cigar bars or stores. One room is built as or converted to a humidor where all the cigars are stored.
Cabinet
Usually placed on the floor as a piece of furniture. Typically holds 1000–5000 cigars.
Personal
A small humidor kept in a convenient location in home or office for personal storage, special events, or aesthetics, usually holding 20–75 cigars. Also known as a "desktop humidor".
Travel
Portable, usually holding 2 to 10 cigars.
Commercially made humidor cases are typically made of wood, although other materials, like acrylic glass and metal, are not uncommon. Carbon fibre, silicon carbide, and polyethylene have also been used. Disregarding aesthetic qualities, the casing's purpose is to protect the interior and create a closed environment, so any durable and airtight material can be used.
The interior is typically a veneer of Spanish cedar, which possesses the following desirable characteristics for cigar storage:
Humidors are typically commercially produced, though most walk-ins are custom built and some humidors are homemade. They range considerably in material, size and complexity. Capacity is determined by deducting the space required for the humidification element and some extra room between the element and the cigars. It can also be calculated online for the most popular cigar formats.