How do I Preserve Documents in a Time Capsule?
The success or failure of a time capsule is dependent on a number of factors: the material the container is made of; the ability of the container to maintain a seal; the environment within the container; the selection, deterioration and interaction of the enclosed artifacts; and the microorganisms that may proliferate within the container under conditions favorable to their growth.
For references and suggestions on construction, preparation of contents, and additional resources, please see the Smithsonian Museum Conservation Institute: Time Capsules web page at Time Capsules.