What humidifier do the luthiers use in their shop? I'm looking for one (prefeably with a big enough tank so I won't have to keep adding water) for my apartment and figured the luthiers would know best.
Once you know what the humidity is where you keep your gear, then you can think about what solution you need to control it. Dry air is a problem in a lot of places in the USA - the desert in the southwest all the way from LA across to Texas, as well as anyplace in the country where it gets really cold in the winter. If you live an a dry area, you know you always have to worry about your acoustic instruments getting too dry. Even in wetter areas, when the heat is on in your house, that's normally when you have to worry about your stuff getting too dry.
In New York, the humidity in my place could easily get into the 20%s in the winter time when the heat is running, so I have a humidifier that's connected to the furnace to moisten the air in the whole house (great help for allergies, keeping down static electricity, and other things in addition to helping protect gear). However, you should have a hygrometer to measure the humidity. Too much can be just as bad as too little. If you keep your place too moist in the winter when it's normally dry, you can have problems with condensation in the attic and other stuff... No matter where you live, I'd recommend keeping track of what the humidity is in your place and take steps to control it from there.
I use two old drum type humidifiers... Each hold about 5.5 gallons of water and need refilling daily to properly humidify mu 2000 sq-feet shop! Found these in flea markets... before, I used newer ones that reqeired frequent filter replacement!!! at about 17$ per filter, it was too expensive to be a long term solution for me!