ExtendedGamutPrintinginFlexographicPackagingPrintingWaynePeachey,SGSInternationalTheUKisknownformanygreatthings…TheBeatles,London,theRoyalFamily,redbuses,fantasticgreencountryside,arichhistory.Itisnotknownforit’sfineweatherandlivingnexttotheAtlanticOceanmeansthecountryexperiencesmorethanit’sfairshareofrain!HowevereveryBritishmalehasoneiteminhiswardrobe,aHawaiianshirt!Thisisthetypeofshirtwithbrightcolours,picturesofpalmtrees,parrots,fish,andwhenthesuneventuallyappearsandwarmstheland,theBritishmaleknowsitistimetowearhisbrightshirtandenjoythesunshineasifhewereonthebeachesofHonolulu!MostHawaiianshirtsintheUKaremorethantenyearsold,theyneverwearout,theyareseldomwornthankstotheBritishclimate!ItcouldbesaidthatExtendedColourGamutistheHawaiianshirtofprinting.Everyfewyearsthereisabuzz,withnewproductsandnewwaysofworking.Testsaresetupandrunonpresses,lotsofexcitementensues,andthenECGisputawaytothebackoftheprintingwardrobeforafewmoreyears.Soitmayseem.However,thebenefitsofECGhavebeenrealizedinmanymarketsanditisalmostanindustrysecretthatmanypressesarerunning24/7withjustonesetofinks,withminimalpresschangeovertimes,minimalinkinventory,andhugelyincreasedpressuptime.ExtendedColourGamutPrintinghasmanydifferentnames,suchasMulticolourPrintingortradenamessuchasOpaltone.Atitscorethetechnologyusesastandardsetofcoloursintheprintingpressthatseldomchange.Whenaspotcolourisneeded(eg.Pantone485),amixoftwoorthreecolourswillbeusedtoget‘veryclose’tothatspecificred.WHICHADDITIONALCOLOURSAREUSED?TypicallyCMYKisused,plustwoorthreecoloursthathelptosignificantlyincreasetheachievablecolourgamut.Cyan,Magenta,YellowandBlacknormallyformthebasisofthecolourset.Thentwoorthreecoloursareaddedandtheseneverchangeinthepress,soinitialchoiceoftheadditionalcoloursisreallyimportant.NormallycoloursmuchbrighterthanCMYareadded,andthesearetypicallychosenfromOrange,Red,Violet,Blue,Green.SotheECGsetcouldbe(forinstance)CMYKRGB,CMYKOGV,CMYKRB,CMYKOG,CMYKOVetc.

ExtendedcolourgamutsvsCMYK,withPantonelibraryoverlaidWHICHSETGIVESTHEGREATESTCOLOURGAMUT?Colourgamutisthesizeofthecolourspacethatcanbeachieved,whencalculatedasanL*a*b*colourspace.TheadditionofOrange,GreenandVioletprovidesthegreatestcolourspace(dependingonthecolourschosen),howeverwhenthesearemixedonpress(usingscreening)theycanpresentmoreregistrationchallengesthancoloursetssuchasCMYKRB.RedandBluearethemostcommonspecialcoloursused.UsingCMYKRBsmallbluetextcanbeachieved,howeverinaCMYKOGVcoloursetthesmallbluetextwouldneedtobemadeupoutofCyanandViolet,whichcouldpresentaregistrationchallenge.Ifcolourgamutisapriority,thenthebrightestcoloursetwouldbeimportant.Ifacustomers’specificbrandcolourismoreimportant,thenyoumaynotwanttouseacoloursetthatgivesyoubetterregistrationandbettercolourconsistency.

Soyoucansee,dependingonyourdesignneeds,youcanchoosethecolourcombinationthatisthebestfit.INPRACTICE,WHATDOPRINTERSUSE?Somecustomershavespecifiedacolourset,suchasCMYKOGV.Theythenrequesttheirprintersstandardizetothis.Othercustomersjustwantgoodqualityprint,butatareasonablecost.Thereforetheyarehappytoswitchtheirworktoaprinters’ownECGworkflow,reapingsavingsinprintingcosts.CMYKRBisverypopular,asRedandBlueareusedofteninpackagingprinting.Greencanbeadded,howeverunlessyouwantyourimages(eg.Lettuce)tobeperfect,greendoesn’taddasmuchtotheimpactofthework.PrinterssometimesadoptaCMYKRGB(forinstance)workflow,andthenonlyusegreenifabsolutelyrequired.ToachievePantonecoloursasaccuratelyaspossible,acoloursetofCMYKOGVwouldberequired.Testingwithaninkcompanywouldbethebestwaytoachievethelargestcolourgamut,andthereforethebestcolourmatchtoasmanyPantonecoloursaspossible.SOBRIGHTERCOLOURSELLS?Yesitdoes,ifaproductpackageisbrighterthanitscompetitorsthenitcanattractshoppers’attention.HoweverECGcansometimesfailifthecoloursaretoobrash,oriftheproductimagesarenotrealistic,orifthecoloursarenotconsistent.WHATARETHEPRACTICALBENEFITSINTHEPRESSROOM?Atypicalflexographicinkroomwillcontainmanyhundredsofpartly-usedinkpails.Thesewillbeleftoverfrompreviousprintruns,andmaybeusedinthefuture.Butnormallythesejustsitaround,andiftheyareusedtheirconditioncanbeanunknownandsoleadtopressdowntimeastheink/solventsmixisbalancedforthejobinthepress.WithECGyoujusthaveseveninks,pluswhite.Whenyoufinishonejobandstartanother,youdonotneedtoreturntheinktotheinkroom,mixupfreshcolours,andthenputthoseinthepress.

Alargeinkinventorycanbereducedtojustsevencolours!Onpressyouwouldremovetheplates(ontheirprintingsleeves),installthenewprintingsleeves,andthenstartupthepress.Thesameinksareused,andsootherthansomeminoradjustmentsthejobisreadytorun.Thesavingsaredependentonspecificsituations.Forinstanceifyoualreadyrunjobsfor24hoursormore,youmaynotseeahugeimprovementinpressuptime.Ifyourtypicalrunsareanhourortwo,andthenyouhavetwohoursofpressdowntimewhilethepressiscleanedupandtheinkschanged,pluscolourmatched,youwouldseesignificantsavings.Inthemostextremecases50%to100%morepressuptimecanbeachievedusingECG.SomecustomersarefullyawareofthepotentialsavingsandarehappytoencourageprinterstomovetoanECGworkflow.Forinstancesupermarketsprintalargerangeofitemsforwhichqualityneedstobeacceptable,butcostshavetobeabsolutelyminimal.ManyintheUKhaveswitchedovertoECGtorealizethecostbenefits,notnecessarilyforthebrightercolourgamutthatcancreatemoreimpactwithinimages.Changingafourcolourjob(forinstance)tobeasevencolourjobdoesnotsimplifyanything,itcancreateadditionalcost.Also,runningECGonlypartofthetimecanbeadisruption.Printerswhotakethisonboardtypicallydedicateoneortwopressestothistypeofwork,andprintothertypeswithtraditionalprintingtechniques.WHATABOUTCOLOURSEPARATION,COLOURPREDICTIONANDCOLOURMATCHING?ThankstomodernprepresscolourprofilingtechniquesasevencolourECGprocesscanbeprofiledaseasilyasafourcolourprocess.Specialsevecolourtargetsareprinteronpressandtheresultingprofiles(createdusingXrite’sProfilemakerorsimilar)canthenbeusedinconjunctionwithacolourripsuchasGMG.SpotcolourscanthenbepredictedusingtoolssuchasXrite’sColorPicker,whichwillprovideabest-colour-breakdownandapredictionofDEcolouraccuracy.

XriteColorPicker,matchingPantone660basedoncolourprofileinformationSpotcolourscanalsobeshownasalarge‘swatchbook’,sothatdesignerscanselectcolourswithconfidence.

AnexampleECGcolourswatchbookthatcanbeprintedoutandsharedwithdesignersColourseparationofimagesislessstraightforward.ItisoftenasubjectivedecisionwhetheraCMYKimageactuallyneedstobeseparatedintosevencolours.Skintonesdonotnormallybenefitfromextracolours,butiftheimagecontainsvegetables,forinstance,theadditionofgreeninlettuceandredinpepperscanreallyimprovetheimage.Thereforecolourseparationcancostalittlemore,duetotheadditionaltimeinvolved.WHATABOUTPLATEANDPRESSTECHNOLOGIES?Inthepastflexographystruggledtoachievegoodsoliddensity.Thereforewhenadarkspotcolourwasused,aheavyaniloxwouldlaydownlotsofink.

ModernprintingmeansthatHDflexoplates,usingsolidscreeningtechniques,canachievedensitiesthatcompetewithlithoandgravure.Thesetypesofplatecanbematchedwithlowvolumeaniloxes(matchedwithhighqualityinks)sothatmidtonetonevaluesarekeptundercontrol.Oncethisisachievable,ECGcanbeconsidered.ECGreliesongoodconsistentresults,andgoodregistration.Repeatabilityisthekeyandjobscanthenrunoneaftertheother,withtheminimumofpressadjustmentsbetween.Thebenefitstotheprinterarethattheirpressescanachievegreateruptime,asno-onepaysforthepresstimewhenitisnotrunning.Thebenefitstothecustomerarealowercostproduct,butwiththesameorhigherquality.WHATABOUTOTHERPRINTPROCESSES?LithohasadoptedECGforyears.Thegreatbenefitisthattheplatesarerelativelyinexpensive,andsojobscanberunincombination(eg.Perhaps24differentdesignsononesheet),withlotsofspotcoloursrepresentedasECG.ScreeningisveryfinewithLithososcreenedspotcoloursarenotnoticed,andregistrationistypicallygoodwithLitho,sothefitbetweenECGandLithoisverygood.Gravurecouldrealizesomeofthebenefits,butthefactthatcylindersaredeliveredtothepresscompletewiththeirinktraysmeansthatthechangeoverdelaysarenotsoprevalent.Possiblygravuremaysufferfromeverycolourbeingscreened,andsosufferwithmoireissues.IhavenotpersonallycomeacrossgravureprinterswhouseECGbutnodoubtsomeoneouttherehasfoundthesametypesofbenefitsasrealizedinFlexo.ExtendedColourGamuthasaplaceinprinting.IthasastrongalthoughdiscreetfootholdinflexographybutonethatIbelievewillgrowduetopricepressuresandduetoit’sflexibility.It’sawin-winformanycustomersandprintersandonethatshouldnotbeoverlooked.SUMMARYOFBENEFITSQuality Enhancementofimages/Additional&morevibrantcolors/Increasedtonalrange/Increased“POP”/ConsistencyofprintprocessTime&CostMake-ReadyTime&MaterialReduction/Inksarealwaysinthepress/Printrotationspre-determined/Ink“Wash-ups”notrequiredaftereveryrunInk6-7basecolors/Nospotcolors!/Reducedinkinventory/Reductionofinkmanagementcosts/Nospecialcolormatching/Greaterinkbatchconsistency/Leveragedinkspendfor6-7basecolorsPrintMix

Commoninkcolorsenablecombinationprintforms/Brandfamiliescanbegangedtogetherinacombinationrun/Reducedfinishedgoodsinventory