Tropical
These climates are characterised by heavy rainfall, high humidity and high temperatures.
When caring for paintings in tropical climates it is important to note that:
insects and moulds thrive and reproduce readily;
chemical deterioration reactions generally proceed faster at higher temperatures;
materials that have been in a tropical environment for some time will have a high moisture content If they are suddenly moved into a drier environment they are likely to suffer shrinkage and warping of the support and stretcher;
many of the materials which make up paintings are very reactive to changes in relative humidity. For example the animal skin glue used as the size will soften; a wooden stretcher may warp, etc.; and
composite works such as collage will be particularly vulnerable.
Controlling moisture is important in a tropical environment.
Condensation may be a problem for glazed works and you may need to consider providing air holes in the backing board to allow adequate air flow. Cover these air holes with gauze to prevent insect entry.
Ensure that your storage and display spaces have good air flow.
For particularly moisture sensitive works you may consider placing RH buffered fabric or silica gel cells within the frame. You will need to discuss this with a conservator.
Note: If your collections of paintings have been kept in a tropical environment for a considerable period and they are stable—do not try to alter the environment to meet the recommended ideal conditions. This could do more harm than good. The emphasis should be on long term stability.