Designation:D5634–01StandardGuideforSelectionofPermanentandDurableOffsetandBookPapers1ThisstandardisissuedunderthefixeddesignationD5634;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisguidecoversoffsetandbookpapers,bothcoatedanduncoated,usedinthepreparationofpermanentrecords.Permanentrecordsusuallyareexpectedtolastseveralhundredyearsinarecordsrepository,withlittlechangeinpropertiesthataffectreadibilityorhandling,althoughsomerecordsareexpectedtohaveshorterlifetimes.1.2Acidicmaterialsincorporatedinpaperduringmanufac-ture(forexample,rosin-alumsizing)contributetodeteriora-tion.Ithasbeenshown(1,2,3,4,5)2thatthelifeexpectancyofuncoatedpapersisanapproximatefunctionofthepHofanaqueousextractofthepaper.1.3Thefollowingwouldbeexpectedtocontributesignifi-cantlytothelifeexpectancyofbooksanddocuments:theuseofpaperswithcontrolledacidityorofpapersmanufacturedunderneutraloralkalineconditions,especiallypaperswithacalciumcarbonatefillerthatabsorbsacidicgasesfromtheatmosphereorcanneutralizeacidicmaterialsformedintheagingofpaper.1.4ThreepHlevelsreflectingthreelevelsoflifeexpectancyareoutlinedinthisguide.AsonecannotrelyonpHaloneasanindicatorofstability,minimumretentionsofpropertiesafteracceleratedagingat90°Cand50%relativehumidityaresuggestedforthethreelevelsoflifeexpectancy.1.5Inselectingpapersforpermanentrecords,paperswithacceptabledurabilityareevaluatedforlifeexpectancythroughacceleratedaging.1.6Thisguideshouldbeusedinthepurchaseofpaperforpermanentrecords.1.7Thisguideisbasedontheuseoffibersourcesusedintheproductionofpaperthatcontainsnomorethan1%ligninforpapersusedinarchives,libraries,andotherpermanentrecords.However,underproperconditions(seeX1.8)papercontainingmorethan1%ligninmaybeemployedformanyotherendusesinpaperforrecordsthatarerequiredtohaveasubstantiallifeexp...
