Choosing the correct place
It is not easy to display a lot of fine pictures in a home. Trying to obtain balance whylst keeping them in a good condition Whether they are lithographs, prints or paintings.
Here are my tips :
1. Sunlight is by far the worst of all, pictures shall fade in just one season. Letting a picture recieve direct sunlight for more than an hour per week is already too much. If left for too long the browns and weaker colours shall start to become purple. That is why we say "Ultra Violet" light. Plants do not fade because they have reflective, or absorbant surfaces. They have a high level of chloryphl too.
2. Draughts are another damaging aspect. Draughts are fine as an entity but they bring with them a certain amount of moisture, so if a draught is reaching a picture then it may be getting damp, and dust. Not good.
3. If you look at really old prints or books you shall ocasionally notice grey black circular spots on them. This is microbial, a sort of disease. It is caused by moisture, cant be reversed.
4. Pictures that have been exposed to all the above conditions shall develop bubbles or "crinkling", this is caused by the dampening of a print, followed by the drying out of it. Paper, like buildings shall change shape seasonally. But if you are not carefull you can create those seasons within one week in a single room.
5. Never get an "airtight" frame in the hope that you have beat the problem, you will just create a "double glazing" atmosphere, moisture will be attracted to the inside of the frame. This is due to temperature differentials in the room.
6. Try it out, next time you have a long shower bring a newspaper in with you, leave it on the top of a surface where no direct water can reach it. Then put it in the living room afterwards, check it the next day and notice the damage.
6. An art gallery shall have a very expensive air conditioning system, and millionaires too of course. Be carefull when using dehumidifiers though as you dont want to dry the room out too much, it shall affect your fine wood furniture and frames.
I hope this has been a help.