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Archival Leaflets - Homemade Humidifier


Mark Shenise, Associate Archivist

Occasionally the archivist/historian will come across rolled up or folded material. The item needs to be flattened for proper storage. This can be done with a homemade humidifier. Please be aware that as in the case of all manually operated devices, great care and attention must be given to the items as they are being humidified. The idea behind this is to safely and slowly get the items damp enough that they can be flattened out, either being unfolded or unrolled. There is always the potential the mold can develop if care is not taken. You do not want to put items in this humidifier if you are not going to be around on a daily basis. In some cases it can take several days for the material to relax. What we are making is a two chamber humidifier. One chamber will hold the water and the second chamber will hold the item. The idea is to get the air inside the chambers damp enough that the item or items, absorb the moisture and become pliable enough that the item(s) can be flattened out under modest pressure. At the same time we want to keep the item(s) away from direct contact with the water. Purchase two plastic trash containers that have a tight seal when the lid is in place. One container should be able to completely fit inside the other. Cut three or four slots near the top of the smaller container. Place the item(s) to be relaxed into the smaller container. Tightly replace the lid and set the container aside. Measure approximately 2 cups of water and pour the liquid into the bottom of the larger container. Never place any liquid in the smaller container! There should be enough water to cover the bottom of the larger container. Center the smaller container that holds the item(s) within the larger container till it rests on the bottom. Close the lid on the larger container. Make sure the seal is tight. With a tight seal the humidity will increase as the water evaporates. The humid air will pass through the slits and be absorbed by the item(s). If possible place the container where it gets some sunlight. Depending on the condition of the items(s) start checking the image(s) after one day. Once the item(s) are relaxed remove them from the smaller container. Don't let the item(s) become soggy or overly damp. They should feel soft to the touch. Prior to removing the item(s) from the smaller container you will have laid out on a flat surface a bottom layer of paper toweling with a top layer of acid-free paper for each item. Place the item on top of this newly constructed blotter. If the item was rolled originally place it so the arc of the role is facing down, not up. Cover the item with a layer of acid-free paper which is then followed by the layer of paper towels. Make sure the blotter material overhangs the actual item. Once you have your sandwiched blotter in place, find some heavy objects, namely books, to use as weights which are then placed directly on top of the blotter. Empty the larger container of its water and allow it to air out. In two days check to see if the item is stable enough to store flat in an acid-free container on a shelf. You may need more blotting time depending on the item. In some cases you may need to repeat the entire process. We have successfully used this procedure on both paper and photographic images.