To do so may damage its aesthetic effect and destroy evidence of authenticity. No picture should be mounted down merely for the sake of removing a few waves or slight buckling in the paper surface. In certain cases it may be necessary to support a fragile or damaged picture by backing it with handmade paper. A picture must never touch the glass, since glass easily condenses moisture and may cause the growth of mold. A piece bought in the dry air of New Mexico may buckle a bit in increased humidity.
Many framers prefer to have a piece cure in the environment before they frame it.
At home, spray glass cleaner on a cloth, rather than directly on the glass surface. The liquid cleaner might drip between the frame and glass, staining the matt or creating humidity in the framed environment. If a piece is kept permanently framed, it is advisable to open and examine it every ten years or so. An Excellent Resource Light Impressions is a catalogue and valuable source of archival supplies for the professional and the layperson who wants to protect, store or display photographs, artwork and papers of all kinds. By Pamela Michaelis publisher of the Wingspread publications.