Preservation is the keeping of records that exist and the safeguarding of them from harm and decomposition. Items to be preserved include letters, documents, maps, books and photos, but not only older pieces. Contemporary items that would be of interest 100 years from now should also be sustained. One key to protecting records is a good knowledge of paper. Most paper created prior to 1900 was made of cotton, which is acid-free and can conceivably last forever.
Paper made of wood pulp is high in acid content.
Newsprint is the worst, as evidenced by the ease and rapidity in which it turns dark and brittle, self-destructing. Depending upon the item, not all steps are involved each time. Ms. Mueller's intention is to provide the layman with low-cost tools and methods to protect their records. For documents that are too brittle to unroll, humidification is the answer. For small items, a tupperware bowl with a lid and a grate in the bottom is used.