The National Endowment for the Humanities, libraries, and library consortia have made significant investments in preservation microfilm during the past 20 years. Is it a viable preservation solution for the next 20? This is an opportune time for technical experts to revisit functional requirements for preservation and to state them in a format-neutral fashion, for use in informing the development of preservation standards, guidelines, products, procedures, and services.Criteria for use, sustainability, and affordability are presented as a draft framework to engage IS&T and other interested professional associations in a discussion of variables relevant to codifying preservation reformatting processes, and to certifying copies according to preservation standards.