When storing paper, the following precautions should always be followed:
Do not store paper where it will be exposed to direct sunlight.
Store all your paper in the same environment - a room where the temperature is 20 25 °C (68 77 °F) and the humidity is 30 65%.
Store on a flat surface.
Do not store paper vertically.
Under high temperature and humidity conditions, or low temperature and humidity conditions, store paper in plastic bags.