Acid Free Paper manufactured to ISO9706 Cream paper 100gsm Archival quality Safe long term preservation of written printed work For notes, printed or handwritten, family tree charts, print outs and general use. It is manufactured to ISO 9706. This means it must conform to a particular set of standards such as pH level, alkaline reserve (calcium carbonate equivalent), tear resistance and resistance to oxidation. It is the alkaline reserve that helps the paper resist contamination from external sources over the years. IMPORTANT: Ensure you use an acid free pen for your written work. Most Inkjet printers have acid free ink.