Furthermore, the tapes or disks may have deteriorated. Include instructions on any intended playback equipment. For computer tapes, add a written copy of the software, and identify the computer type. Photographic films coated on a polyester base rather than an acetate base are more stable. Color prints and slides can fade even when kept in the dark.
Newsprint is acidic and deteriorates easily.
A local museum or library should have names of paper conservators who can deacidify newspapers for you. Objects made of rubber should not be placed in time capsules since rubber deteriorates over time, releasing sulfur. All wood, especially oak, gives off acid vapors and must be sealed away from electronic equipment or metal articles, especially those made of lead, or lead-containing alloys, in the time capsule. Textiles should be clean and insect free. Acts as a humidity buffer if temperature changes.