Designation:D4303−10StandardTestMethodsforLightfastnessofColorantsUsedinArtists’Materials1ThisstandardisissuedunderthefixeddesignationD4303;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Fourtestmethodstoacceleratetheeffectsoflongtermindoorilluminationonartists’materialsaredescribedbelow.Oneofthenaturaldaylightmethodsandoneofthexenon-arcmethodsareusedtocategorizethelightfastnessofcolorants.1.1.1TestMethodA—ExposureinsouthernFloridatonaturaldaylightfilteredthroughwindowglass.1.1.2TestMethodB—ExposureinArizonatonaturalday-lightfilteredthroughwindowglass.1.1.3TestMethodC—Exposureinanon-humiditycon-trolledxenon-arcdevicesimulatingdaylightfilteredthroughwindowglass.1.1.4TestMethodD—Exposureinahumiditycontrolledxenon-arcdevicesimulatingdaylightfilteredthroughwindowglass.1.2Thesetestmethodsareusedtoapproximatethecolorchangethatcanbeexpectedovertimeincolorantsusedinartists’materialsexposedindoorstodaylightthroughwindowglass.NOTE1—Thecolorchangesthatresultfromacceleratedexposuremaynotduplicatetheresultsofnormalindoorexposureinahome,artgallery,ormuseum.Therelativeresistancetochange,however,canbeestablishedsocoloredmaterialscanbeassignedtocategoriesofrelativelightfastness.NOTE2—UserswhowishtotestcoloredmaterialsunderfluorescentilluminationshouldconsultPracticeD4674.1.3Lightfastnesscategoriesareestablishedtowhichcolo-rantsareassignedbasedonthecolordifferencebetweenspecimensbeforeandafterexposure.1.4ColordifferenceunitsarecalculatedbytheCIE1976L*a*b*colordifferenceequation.1.5Thesetestmethodsapplytocoloredartists’materials.1.6ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.7Thisstandarddoesnotpurporttoaddressthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstanda...
