It is necessary to house select records below -5°C to slow the rate of degradation. When purchasing a freezer, ensure that it is frost-free and that there is a digital monitor on the exterior that supplies temperature and humidity readings.
To control the humidity of the freezer, it is important to use baked mat board when rehousing your records in preparation for freezing. Baking the pieces of mat board prior to use will thoroughly dry them out. The mat board should be baked in a standard convection oven for 3 – 5 minutes at 100°C. Ensure all areas of the mat board is exposed to the heat. Once it is removed from the oven, let it cool down and then use right away so that it does not begin to absorb moisture. It is recommended to sand the corners of the pieces of mat board so they do not puncture the bags.
For full instructions on freezing records, please see our guide, found in Preparing for Digitization, Temporary Housing: http://archivesalberta.org/doc/Preparing_for_Digitization_Handout.pdf