It is no longer a disposable commodity but is seen as of long term significance. The repository must make a decision whether to allow patrons to browse through non-circulating materials or to close the stacks. If the stacks are closed it will provide more protection but will require additional staff time to retrieve items. Dedicate a restricted access area for rare or archival materials. Removing items from circulation and placing them in a dedicated area go hand in hand.
Some libraries place their rarest items in a locked case or a special room.
At the very least, a dedicated area is needed for the non-circulating materials. I strongly recommend that there be a dedicated area for storage. This will make it possible to maintain additional control over the materials and provided for their preservation. Most archives and many libraries have a closed-stacks area which is accessible only with the help of a staff person. Give some thought to environmental considerations - particularly light and humidity.