Use Bookkeeper? Deacidification Spray to safely and effectively neutralize acids in paper and increase the life of your books, documents, manuscripts, clippings, maps, posters and more. The spray's magnesium oxide neutralizes acid leaving an alkaline reserve permanently fixed in the cellulose fibers. Unlike some other deacidification sprays, Bookkeeper?r won't clog and it works on all materials without negative impact on print or colors. Books & records treated with Bookkeeper?r lasts 3 to 5 times longer than untreated material, allowing them to be used by historians and researchers for centuries into the future. 22oz (900gm) refill bottle. Safely and effectively neutralizes acids in paper. Virtually odorless and dries in minutes. Won't negatively affect print or colors. Nontoxic, non-flammable, and environmentally safe. Contains no atmosphere damaging CFCs nor Freon. Always test in an inconspicuous spot before treating item. Same trusted ingredients as Archival Mist.