How do you avoid moisture between the glass of the frame and the photo?
When actual moisture condenses on the glass in a picture frame, the most common cause is high relative humidity followed by a drop in temperature. This is actually fairly uncommon in most household environments, unless the item hangs in a bathroom. In this case, moisture on the glass is practically unavoidable. The best way to avoid this is to hang the picture in an area with lower humidity and stable temperature.
If a photograph is framed in a manner such that it directly contacts the glass, it can appear "wet" even though the effect is just caused by the photo's emulsion clinging to the glass. Over time, a photo in direct contact with the glass will tend to stick, which can ruin the photo. For this reason, you always want to allow a bit of space between the photo and the glass, which can either be provided through the use of a mat or plastic spacers.
