Designation:D3258−04(Reapproved2019)StandardTestMethodforPorosityofWhiteorNearWhitePaintFilmsbyStaining1ThisstandardisissuedunderthefixeddesignationD3258;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationoftheporos-ityofawhiteornearwhitemineralspiritsinsolublepaintfilmtoindicatethedegreetowhichasubsequentcoatwillpen-etrate.1.2Thetextureofthefilmcanaffectcleanupthatwillinfluencetheresultsofthetest.Astainappliedtoahigh-hidingpaintwillnotlowerthereflectanceasmuchasthesamestainappliedtoalow-hidingpaintofequalporosity.Thesepointsmustbeconsideredincomparingdifferentpaints.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2E1347TestMethodforColorandColor-DifferenceMea-surementbyTristimulusColorimetry3.SummaryofTestMethod3.1Thetestpaintisappliedtoanonporoussurface,airdried,thenmeasuredforreflectance.Aspecialcoloredpen-etratingmediumisapplied,theexcessremovedinaspecifiedmanner,andreflectancemeasuredagain.Thedifferencebe-tweenthetworeadingsindicatesthedegreeofporosity;thesmallerthedifference,thelowertheporosityofthefilmandthegreateritsabilitytoresistpenetration.4.ApparatusandMaterials4.1FilmApplicator...
