This document discusses preservation and conservation of historical documents. It begins with an overview of different mediums used over time for bearing information, such as clay, papyrus, paper and microfilm. It then shows examples of illuminated manuscripts, incunables, and block books. The document outlines key aspects of preservation and conservation such as cooperation, education, and disaster preparedness. It discusses various methods for paper deacidification and shows examples of damage from water, mold, ink corrosion and the vinegar syndrome affecting microfilms. The document concludes with basic considerations for preservation and restoration of books as cultural assets, including discussions on originality, minimal intervention and reversibility of restoration methods.