printing technology course documentation
DESCRIPTION
A documentation of my course learning in semester5TRANSCRIPT
i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Introduction to Printing Technology
reuben dsilva semester iv
i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
“What gunpowder did for war, the printing press has done for the mind.”
~ Wendell Phillips
3i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
This document aims at outlining the process of graphic
print production from start to f inish based on the order
of my understanding hence far.
_ Timeline
_ Pre Press
Scanning
Coloursetting,
Halftone
Paper
Imposition
Plateproduction
Ink
Costing
_ Press
Relief
Letterpress
Flexography
Offset
Gravure
Screen
Unconventional
_ Post Press
Methods
Binding
_ Field Visit
_ Reference
04
06
08
11
14
18
26
27
30
32
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42
46
48
50
53
54
4 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
TimelinePrinting is an industrial process of duplicating or
developing an original for production of text and images,
typically with ink on paper using printing press.
0105 InventionofpaperbyChinese.
0200 Woodblockprinting
0868 Diamondsutra,theearliestprintedblock.
1450JohannGuttenburg,Themovabletype.
1500Etchinginvented.
1655 Oldestexistingnewspaper,TheLondonGazette.
1798 LithographyinventedbyAloisSenefelder.
1867 Typewriterwaspatented.
1871 MonotypebyTolbertLanston.
1887 GelatinBromidedryplate.
1962 Offsetwasinvented.
1969 Laserprinting.
1973 Compugraphics/videosetter.
1977 LinotypeintroducedLinotron.
1978MonotypeintroducedLasercomputer.
1985Rasterimageprocessor/Desktopcomputers.
1991IntroductionofDirectImagingTechnology.
1995 Touchscreenprocesscontrol.
2000Digitalworkflow.
5i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
6 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
ScanningVery often the images to be printed must be lifted of f
existing originals. The f irst step in digitizing an
original is scanning.
Thescannerisadevicethatopticallyreadsimages
andconvertsittoadigitalimage.Themaximum
resolutionofyourscannersetsthelimitationon
howmuchyoucanenlargeyourimage.Thereare
twofactorstoconsidertodetermineresolutionof
scanning:thescreenfrequencyandwhetherornot
yourequiretochangethesizeoftheimage.Screen
frequencyisdeterminedbyprintingmethodand
paperused.
Therelationshipbetweenimageresolution
andscreenfrequencyiscalled‘sampling factor.’
Optimumsamplingfactoris2,whichmeans
thattheimagetobeprintedon150lpishouldbe
scannedat300ppi.Ifsamplingfactorgoesdownto
1,pixelswillbevisible.
Listofrecommendedscreenfrequencies:
Paper
Newsprint:65-85lpi
Uncoated:100-133lpi
Coatedmatte:133-170lpi
Coatedglossy:150-300lpi
Print method
Offset:65-300lpi
Screen:50-100lpi
Gravure:120-200lpi
Flexographic:90-120lpi
7i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Scalingfactordescribestheratioofthe
originalscannedimagetothesizeatwhichit
istobeprinted.
Optimalscanningresolution=Screen
frequencyxSamplingfactorxScaling
factor(%)
ScannersmostcommonlyusedareCCD
flatbedscanners.
Afterscanning,wemustadjustthegamma
curvedependingontheblack/whiteareasin
animageso thatdetailsarenotlost.Gamma
value<1.8forsnowimages/Gammavalue>1.8
fordarkimages.
Also,itisadvisabletosharpenthe
imageifitapperasslightlysoft.Thiswill
assuregoodresultswhenprinting.
Types of originals
Line art:Blackandwhitemageswithouttonal
variationslikealinedrawinginpen.
Continuos tone:Agrayscaleorcolourimage
havingsmoothcontinuouslyvaryingtonal
rangelikeaphotograph.
Originalsnotsuitableforreproductionmay
containstains,dust,scratches,mattfinish.
Care for originals
Neverwriteonthebackofphotographhs
Coveroriginalswithatracingsheet
Donottouchanoriginalwithoilyhands.
Donotcliporstapleoriginals.
Continuous tone
Halft one
8 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Colour“I’ve handled colour as a man should behave. You may
conclude that I consider ethics and aesthetics as one.”
~ Josef AlbersChromaticsorunderstandingcolouriscrucial
inprinting.Everyimagecontainsthousandsof
differentcolours.Itisnotpossibletousethousand
differentinksorlightsourcestorepresenteach.
Therefore,wefoolthebrainintoperceivingthese
coloursbymixingthreeprimarycoloursand
approximatingthethousands.
Additive colour mixing
Additivecolourmoxinginvolvesaddingsome
amountofred,greenandbluelighttocreatenew
colours.
Ifyoumixallthreeatfullintensity,yougetwhite.
Atalowerintensity,anequalmixofallwillgivea
gray.Twocoloursatmaximumintensitywithouta
thirdgivesyoufollowingresults.
Blue+Green=Cyan(C)
Red+Blue=Magenta(M)
Red+Green=Yellow(Y)
Subtractive colour mixing
Inprinting,coloursarecreatedbymixingthree
primarycoloredprintinginks.Cyan,Magentaand
Yellow.(CMY).Thismethodiscalled‘subtractive
colourmixing.’
Cyaninkabsorbsalltheredlightandreflects
greenandblue
Magentainkabsorbsgreenlightandreflectsred
andblue.
Yellowinkabsorbsallthebluelightandreflects
redandgreen.
Theyarehenceknownas‘subtractive primaries’.
9i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Colour Gamut
Thecolourgamutistherangeofcoloursthat
canbetheoreticallybecreatedwithina
particularcolourmodel.Different colour
modelshavedifferentgamuts.Thewiderthe
colourgamut,themorecoloursyoucancreate
withthatmodel.
RGB has a wider gamut than CMYK. Even
thoughaCMYKfilehasmorebitsperpixel,
it’ssensitivityrangeislimited.Anextended
colourgamutbeyondRGB,iscalledHigh
Fidelityprinting(HiFi).Thesemaybeusedin
multicolourconversionsofuptosix-colour
printing.
Spot colour
Inmulti-colourprinting(four,fiveorsixcolour)
theadditionalchannelisoftena‘spot’colour.
Thismaybeaspecialsecondarycolouror
gold/silver.ItmaybeselectedfromPantone
shades.
Black: theory versus practice
Ifyouprintcyanovermagentaoveryellow,the
resultshouldbeblack.Inpractice,itturnsout
tobeadarkbrownishgray.That’swhyablack
printinginkisaddedtothismodel.Thisblack
isreferredtoas‘registration black.’Itisdebated
whetherKcomesfrom‘key’colourorthe‘k’
inblack.
10 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Imagesexistindifferentmodesdigitally.
Bitmap
Lineartconsistsofblackorwhitepixelsbutno
mid-rangetones.
Grayscale
Animagethathastonesrangingfrom0%black
to100%black.Usually256steps.
Index
Animageinindexcolourcandisplayupto256
colourswithinaspecifiedpalette.Thismeasn
thatallthepixelsintheimagehaveavalue
between1and256basedonthecolourpalette.
ItisoftenusedbysavingGIFformatforwebuse
toreducetheimagesize.
11i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Duoton/Tritone
Two/Threeprintinginksareusedinsteadof
one.Usuallyyouprintwithblackplusone
spotcolour.TIFFformatdoesnotsupport
duotones.
RGB
Thisisthesystemusedincolourmonitors
andphotographicimaging.Eachpixelonyour
screenhasavalueforhowmuchred,green
andblueitcontains.AnRGBimageconsists
ofthreeseparatepixelimages.RGBgamutof
coloursisthelargestandcontainsunto16.7
millioncolours.
CMYK
ACMYKimagecanbeimaginedtobe
separatedintofourseparategrayscaleimages.
Eachoneoftheseimagesdefinestheamount
ofeachrespectiveprintinginkused.
12 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Memory
Bitmap:1bitperpixel=2^1=2tones.
Grayscale:4to8bitsperpixel=16to256scale
tones.
Indexcolour:8bitsperpixel=256colours.
Duotone:8bitsperpixel=256tones.
RGB:24bitsperpixel(8bitsperchannel)=2^24=
16.7millioncolours.
CMYK:32bitsperpixel(8bitsperchannel)=
2^32=4.3billioncolours.
Getting the right colours in print!
Oneofthegreatestchallengesinproducingcolour
forprintingismakingsurethatthecoloursyou
choosearethesameasthatwhichareprinted.The
followingparametersaffectthis.
Colour model
Ifyou’reprintinginsixcolours,youwillget
alargergamutandbetterrangeofhuesas
comparedtoCMYK.Hence,yourpositives
canbeseparatedfromanRGBimage.
Paper
Mostpapershaveaslighttint.Othersmaybe
glosscoated.Reflectivityofthepaperaffectsits
tonalrange.
Printing process
Thicknessofinksusedindifferentprocesses
maybedifferent.Moreink,widerthetonal
range.
Ink
Inreality.yourinkscannotpreciselyreproduce
thesecoloursexactly.Thecloserthepigments
aretothetheoreticalvalues,betterthecolour
consistency.
13i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
HalftoneHalftone is a reprographic technique that simulates
continuos tone imagery through the use of dot lines, varying
either in size or spacing.
Aprintingpresscannotproducecontinuostones
likeinaphotographwithsmoothtonaltransitions.
Itcanonlyprintwithorwithoutcolour.Hence,
halftonescreenisusedtocreateanillusionof
continuostone.
Halftone screen
Toreproducetonesinprint,youuseahalftone
screen.Halftonescreensconsistofsmalloptsin
closelyspacedrows.Theirsizevariesdependingon
whichtoneyouwanttosimulate.Thevaryingdots
createanillusionofacontinuostone.Itisasheetof
glassorfilm.Halftonescreensarecalculatedbya
RasterImageProcessor(RIP).
Screen frequency
Thescreenfrequencyisthemeasurementofthe
numberofhalftonecellsperline.Itismeasuredin
linesperinch(lpi).Thelowerthescreenfrequency,
thelargerthehalftonecellandlargerthehalftone
dot.Thismeansthatthesizeofadotprintedwith
a60lpiscreenwillbe4timesthesizeofthesame
dotprintedona120lpiscreen.Thevariablesthat
helpdecideappropriatescreenrulingare:viewing
distance,processofreproductionandtypeof
paper.
14 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Paper
Newsprint65-85lpi
Uncoated100-133lpi
Coatedmatte133-170lpi
Coatedglossy150-300lpi
Printing method
Offset65-300lpi
Screen50-100lpi
Gravure120-200lpi
Flexo90-120lpi.
Output resolution
Whenfilmisoutputtoanimagesetter,an
outputresolutionmustbeset.Othersetting
includeno.ofexposurepointsperunitlength.
Higherthescreenfrequency,highertheoutput
resolution.
Screen angle
Thebraincanperceivepatternsinvolving0
and90degreeangles.Halftonescreensare
thereforetiltedat45degreestomakepatterns
lessrecognizable.Hence,blackwhichis
themostdistractingcolourisorientedat45
degrees.Yellowwhichistheleastdistracting
colouriskeptat0degrees.CyanandMagenta
areorienteduniformlycloseto45degreesat
15and75degreesrespectively.Thisgivesan
evendisplacementof30degrees.Theseangles
applytooffsetprinting.Gravureandscreen
printinghavedifferentangles.
15i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Moire
Itisthecaseinwhichimproperlysetscreenangles
resultinformationofpatterns.Byassigning
differentscreenfrequenciesfordifferentinksor
changingthescreenangles,thiscanbeavoided.
Rosette
Well-registeredscreensresultinarosettepattern.
Therearetwomaintypesofrosettes:thosewith
anopencentreandthosewithadotinthecentre.
Thepatternmaybemoreevidentinareasofless
coverageandonhigherqualitypaperbutless
evidentonsaynewsprint.
Density
Itisthemeasureoftonalvaluesoftheoriginalor
printedimage.Itismeasuredbyadensitometer.
FM vs Traditional halftone
InFMscreening,thehalftonedotsareofthe
samesizebutatvaryingdistances.Intraditional
halftone,thehalftonedotsareofvaryingsizebut
atuniformdistances.IntheFMtechnique,the
exposuredotsarespreadevenlythroughoutthe
cellwhereasintraditionalthedotsarecollected
inthecentre.FMscreeninggenerallyallowsfor
betterreproductionofdetailthantraditional
screening.LaserjetusesAMhalftonewhileInkjet
printersuseFMhalftone.
conventional flat tint
conventional half tone
first order stochastic
second order stochastic
16 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Paper
PaperwasfirstusedinEgyptandwascalledso
becauseitwasderivedfrom‘papyrus’.Itwasalso
aroundthesametimemadeinChinafrombone.
Theuseofwoodpulptoproducepaperbegan
around105AD.Theprocesstakesplaceinthe
followingorder:
Rawmaterial
Chipping
Pulping
Bleaching
Additives
Dehydration
Paper!
Types of paper
Construction paper:coloured,coarse,large,slightly
rough,‘chart’paper.
Inkjet paper:weight,brightness,coatedsurfaceto
preventinkspread.
Photo paper:typeofinkjetpaper,glossy,matte/semi-
matte,silk.
Glossy photo paper:vividlook,highcolour
density(DMAX),widecolourgamut,
everyday(HP),premiumhighgloss(Epson),
Ultima(Kodak).
Paper surfaces
Uncoated papers:havenoaddedlayeronthe
surfaceandarecompletelynatural;however,the
surfacemaybesizedwithstarch.Uncoatedpapers
The tangible element that has continuously fed into
society through print media, advertising, education
and other traditional forms of resources, sales and
information gathering.
17i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
receivetheirsmoothnessinthecalendaringstack,
aregenerallymoreabsorbentthancoatedpapers
andareavailableinmanydifferenttextures,
colors,weightsandfinishes.Coatedpapers,in
contrast,haveasmootherfinish,aren’tveryporous
andmaybecalenderedorsuper-calenderedoff
thepapermakingmachine.Inkwill,moreorless,
sitonacoatedpaper’ssurfaceandtakelongerto
dry-producingsharper,brighterimaginesbecause
theinkdoesn’tbleedintothepaperandblurthe
halftonescreen.
Coated paper:Coatingproducespaperswith
excellentinkholdout,whichisidealforcolor
reproduction—detailisnotlostandfinetext
holdsupwell—makingthemapopularchoice
forproductsrangingfrombooksandmagazines
toannualreportsandadvertisingsupplements.
Coatedpapersareoftencalledartpapersandare
commonlyfoundinglossyartbooksandtextbooks
containingphotographsorillustrations.Theyhave
exceptionalrunnabilityandprintability,aswellas
aconsistentlyhigh-qualitysurface,stiffness,bulk
andopacity.
Paper sizes
Paperisavailableintwostandards:Britishand
International.IntheBritishsystem,thefollowing
dimensionsarefollowed:
Fullscap13.5x17in
Demy 17.5x22.5in
Medium18x23in
Royal20x25in
Crown15x20in
Imperial22x30in
18 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Bymultiplyingtheshortersidebytwoand
retainingthelongersidewecanobtain‘Quad’
sizes.
IntheInternationalsystem,thereare3
standards.
Asize:Usedforstationerypurposes
Bsize:Posters
Csize:Envelopes.
Theproportionofallthreeare1:1.414.What
changesaretheir‘0’sizes.C0>B0>A0.
Paper qualities
Newsprint:Lowcost,lowquality,non-
archivalpaper,madebymechanicalpulping,
brittlewithweakbind.
Wove paper:Usedinbillandrecordbooks.
Bond paper:Writingpaperusedinbanks
andoffices,Letterheadsandstationery,rag
pulp,50GSM+
Tracing paper:Translucent,oilresistant,
impervioustowater/gas
Map litho:Smoothtopside,usedforbook
andleaflets,80GSM.
Offset:Roughonbothsides,ragpulp,
80-100GSM.
Duplex board:Boxboardusedtomake
cartons
Cartridge paper:Mostexpensive,rag
content,canbepreservedandhenceusedin
certificateandstamppaper.
Chromo paper:Onesidecoated,80GSM
Art paper:Chinaclaycoatingcoversthe
poroussurfacegivingitasmoothfinish,less
C0 1000 x 1414 mm
B0 917 x 1297 mm
A0 841 x 1189 mm
A0 841 x 1189 mm
A1 594 x 841 mm
A2 420 x 594 mm
A3 297 x 420 mm
A4 210 x 297 mm
√2 proportion
A1
A2 A3
A4
Folio division
Relative sizes
19i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
absorptionofink,goodinkdepth,matt/
gloss,100GSM+
Mirror coat:CastcoatedwithChinaclay,
mirrorfinish
Card:Thickerpaper,210GSM+,soldin
gross(144nos.)
Paper weight
ByBrirtishstandard,paperissoldin‘reams’.
Onereamcontains500sheets.Theconvention
followedinspecifyingpaperisasfollows:
Theweightperreamgivesanindicationofthe
thicknessofthepaper.Sincetheno.ofsheets
inareamareconstant,agreaterwt./ream
figurewouldmeanapaperofhigherGSM.
Thecostperkg.isalsospecified.Hence,Cost
ofonereamcanbecalculated.
Grain
Grainreferstothedirectionofthefibersin
asheetofpaper.Inlonggrainpaper,fibers
runinthesamedirectionasthelongest
measurementofthepaper.Inshortgrain
paper,fibersruninthesamedirectionasthe
shortestmeasurement.Withsheetpaper,short
graindirectionisindicatedbyunderscoring(or
bolding)thedimensionalongwhichthegrain
lies,orbychangingtheorderofthenumbers.
Paper quality. width x length x wt. of a ream in kg.
20 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
ImpositionHalftone is a reprographic technique that simulates
continuos tone imagery through the use of dot lines,
varying either in size or spacing.
Printingpressesareknowntobethecostliestunit
perhourinthegraphicproductionprocess.Wecan
minimizetimespentprintingmybyusingoptimally
largesheets.Mostprintingpresseshaveamaximum
paperformatof4,6,16,32pages.Impositioncan
bedoneeithermanuallyordigitally.Inmanual
imposition,everypageoftheprintedproducthas
beenoutputontoaseparatefilm.Thepagesare
placedaccordingtotheimpositionschemeand
mountedontoalargertransparentfilmwithtape.
Thecompletedtransparencyisthenexposedontoa
plate.Digitalimpositionmeansthatyouimposeitin
alayoutingsoftware.Thiscanconsiderablyreduce
costespeciallyiftheproducthasmanypages.
The Makeready
Amakereadyinvolvesalltheactivitiesperformed
untilyougetthefirstapprovedprintedsheet.The
numberofmake-readiesmustbeminimizedto
minimizecost.Itincludesthefollowingsteps:
Printingplatemakeready
Settingthefeeder
Registeringthesheets
Pre-settingtheinkscrews
Ink-waterbalance
Registrationcheck
Inkcoveragecheck
Correspondencetoproofcolours
21i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
4-page sheetwise imposition (folio)
8-page half-sheet work imposition ( quarto)
12-page imposition (12mo)
24-page imposition (24mo)
32-page imposition
22 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
What affects imposition?
1. Design:Themostimportantfactoristhe
layoutwhichistheformatandplacement
ofimages.Thisdeterminesthenumberof
platesneeded.Fewertheplatethefasterthe
makeready.
2.Type of Press:Machineshavelimitsonsize
ofsheetstheycanhandleandnumberoffolds
theycanmake.Typeofpaper/orientation
beingusedistobeconsiderediffoldingmust
takeplace.
3. Budget:Ifyouhaveastrictbudgetyou
maybeforcedtoreducenumberofplatesby
changinga4page/sheetformattoa16page
persheetformat.Thiswouldgiveyouthe
samecontentwithhalfthenumberofplates
thusreducingcostsconsiderably.
Types of Imposition
One side
Itisthesimplestformofimposition.One
printingplateisusedtoprintononesideofthe
printingsheet.Thisiscommoninsmalloffset
pressoperations.
Sheetwise
Themostcommonmethodofimpositionis
calledsheetwiseorworkandback.Withthis
typeofimposition,eachsideofthesheetgets
it’sownmakeready.Hence,twoplatesper
sheet.Thesideofthesheetcontainingthefirst
andlastpage(iftheproductcontains4+pages)
iscalledthefirstform.Thesheetcontaining
23i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
page2andthesecondlasttobeprintedon
theothersideiscalledtheinnerform.
Halfsheet work
Thisoccursinasituationwherethesheet
hasspaceforatleasttwiceasmanypagesas
thedocumentcontains.Forexampleifiwish
toprintan8pagebooklet,mysheetmustbe
capableofholdinga16pageimposition.In
thismethod,oneplatecontainingthefirst
formandinnerformgivesoneimpression.
Thesheetisthenreversedandthesame
plateimpressestheotherside.Hence,two
copiesareobtainedfromonesheetandone
plate.
Thisprocessofreversalofthesheetcanbe
doneintwoways:
1. Work and Turn:Thesheetisrotatedby180
aswellasturnedover.Hence,asinglegripper
edgeisusedforbothimpressions.
2.Work and Tumble:Thepaperisrotated
by180andflippedheadoverheels.Hence,
twogripperedgesareused.Workandturn
methodispreferredbecauseithelpsavoid
misregistration.Also,gripperedgetakesa
marginofhalfinch.Bykeepingno.ofgripper
edgesatoneweallowformoreavailable
printingarea.
24 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Ganged-Up
Dependingonhowmanycopiesoftheproduct
youplaceonthesheet,thisimpositionis
referredtoas2-up,3-upetc.Thismethodis
usuallyusediftheproducthasjustoneortwo
printedpages.
Signature
Heretheimpositionisdecideduponbyfirst
foldingthepaperandlabelingtherespective
orderofpagesandthenimposingthepages.
Sincethepaperisfoldedintohalf,signatures
arein4xmultiples.Forexample,4-page
signature,8-pagesignature,12-pagesignature,
16-pagesignature.
Creep
Inthecaseofacentre-staplebind,thepages
ofthefoldedproductarepushedoutwards
causingtheimageareaofthepagesinthe
centretomovefurtherawayfromthegutter
thanthoseinthebeginningandend.You
havetocompensateforthisintheimposition
processbyfirstmakingadummytomeasure
thecreepoftheinnermostpageandthen
reducetheinnermarginbyafactorinallthe
pagesproceedingfromtheinnermosttothe
firstform.
Untrimmed creep
Trimmed
25i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
4-page signature
8-page signature 16-page signature
12-page signature
26 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Plate-making
Theprintingplatesuseddependsonthetypeofpress,
theprintingmethod,andquantityoftheprintrun.
Aplateispreparedforeachcolorused,orfourplates
inthecaseof4-color(CMYK)processprinting.Itis
basicallyaprocessbywhichthedigitalfilepositiveis
transferredontotheprintingplatewhichisthenused
forprinting.
Thefollowingaresomemethodsofplatemaking:
Image setter
Animagesetterexposesordevelopsphotosensitive
filmorpaper.Ithasahigherresolutionthanthe
printer.Thismaybeanegativewhichwouldhaveto
beexposedtogenerateapositive.
Offset plate
Inthistheexposedfilmisdevelopedbyanonline
developer.Theimagesetter’sRIPcalculateshalftone
screencreatingalargebitmap.Averyfinelaserbeam
exposestheareasofthefilmthatshouldbeexposed.
Thisexposureisthendeveloped.
PS plate
Aftertheplateisexposedanddeveloped,itundergoes
gumming.Gummingpreventsoxidationofplateand
makesnon-printingareawaterreceptive.
Computer to plate(C2P)
Thisisamoreadvancedtechnologywherethe
positivefromthecomputergivestheplatedirectly.
ThistypewasobservedatArt-o-print.
27i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Inks
InkswerefirstmadeinancientChinaaslong
as50centuriesago.Theyweremadefromsoot
suspendedinvegetableoil.Eventually,petroleum
wasusedininks,whichmadethemcheaperand
morepopularforoffsetprinting.Bythe1960s,
petroleum-basedinkshadcompletelyreplaced
vegetable-basedinksintheprintingindustry.
However,petroleum-basedinksarenotwithout
theircoststotheenvironment.Theycontaina
varietyofheavymetals(barium,copper,zinc)
thatleachintosoilandgroundwater.Volatile
organiccompounds(VOCs)arealsoreleased
bypetroleum-basedinks.Thesecontribute
tosmoginadditiontobeingirritatingtothe
humanrespiratorysystem.Whenconsideringthe
sustainabilityofprinting,VOCsemittedduring
theprintingprocessandtheuseofnon-renewable
resourcesandheavymetalsinpigmentsmustbe
considered.Designersshouldspeakwiththeir
printertokeepthesefactorsinmind.
Nearlyallinkscanbeplacedintothefollowing
categories.
Standardprintinginks:Weboffset,sheetfed,
processink.
Specialityinks:Metallic,fluorescent,security,
phosphorescent.
Ink Ingredients
Pigments:Theingredientthatcontributestothe
colouroftheink.
Vehicle: Substanceintheinkthatcarriesthe
28 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
pigmentandbindsittotheprintedsurface.It
maybeoilorwater.
Modifier:Theychangethepropertiesofinks
sothatitcanfulfilltherequirementsofdifferent
typesofprintprocessesandapplications.
Driers:Speedupdryingofink.
Anti-skinning agent:Theseareagentsthat
keeptheinkfromdryingtoorapidlyand
skinningovertheinkfountain.
Extenders:Increasethecoverageofthe
pigmentink.
Distillers:Improvetheflowofink.
Ink characteristics
Body:Consistencyofink.
Tack:Thestickinessoftheink.
Viscosity:Thedegreetowhichinkresistsflow
whenitisunderforcesuchaswhenitisinthe
rollertrain.
Length:Abilityofinktoflow.
Opacity:Thecoveringpowerofink.
Tinting strength:Abilityofaninkcolour
toproduceatintwiththeadditionofwhite
pigmentandreferredtoascoloringpowder.
Permanency:Degreetowhichprintedink
resiststhefadingpoweroflight.
Dryingofinkmaybedonebyabsorption,heat,
precipitationoroxidation.
Ink issues
Set off:Excessiveorslowdryinginktransfersto
othersheet.
Slow drying:Smudgeorsmears.
29i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Poor binding:Dryinkscrapingoffthe
substrate.
Ink adhesion:Poorlyadjustedpresssetting.
Mottling:Unevenabsorptiondueto
inappropriatepaperorpooradjustment.
Special Inks
Scented Ink:Theyarearewaterbasedand
canonlybeprintedonunsealedpaperor
board.Scentedinkscomeinawidevariety
ofsmellsandcanalsobesynthesizedtousea
specificfragrance.Thesmellsaresuspendedin
asemi-clearbaseandthenscreen-printedonto
therequiredsubstrate.
Heat-Sensitive:Theseinkshavealimited
rangeofcolors.Blacktendstoproducethe
mostdramaticresults.Theheat-sensitive
componentissuspendedinasemi-clear
baseandthenscreenprinted.Thereactive
temperaturecanbechangedinaccordance
withclimaticconditions.Likescentedinks,
heat-sensitiveinksarewaterbasedandwork
bestonuncoatedpapersubstrates.Theycan
bemadetoworkonplasticafteranumberof
layersareapplied.Thisisatimeconsuming
processmakingitnotcosteffective.Heat-
sensitiveinkhasthetendencytoscuffwhennot
properly.
Pearlescent & Iridescent: Theseinkscan
beusedwithavarietyofsubstratesand,
dependingonproximity,createadifferent
shadeofmetalliccolorwhenviewing.Theyare
mostcommonlyfoundongiftcards.Theycan
alsoworkwellassolidareaswithtextontop.
30 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
CostingCase1: Offset printing Poster
No.ofcolours:2
No.ofsides:1
Unfinishedsize:23”x36”
Finishedsize:23”x12”
Quantity:4000(+100test)=4100nos.
Paper:BallapurOffsetpaper23”x36”x26.6kg
Paperquantity:3posterspersheet
No.ofsheets=4100/3=1366
No.ofreams=1366/500=2.8ream(appx.3ream.)
Papercost:Cost/kg=Rs.50/-
Costof26.6kg(1ream)=26.6x50=Rs.1330/-
Costof3ream=1330x3=Rs.3990/-………Cost A
Positive:11”x22”=27cmx57cm=1653sq.com.
Cost/sq.cm.=0.75p/sq.cm.
Costofpositive=1653x0.75=Rs.1240/-…….Cost B
Platecost:Oneplate=Rs.600/-
2colourprint=2plates-Rs.1200/-……………Cost C
Printing:No.ofplatesxNo.ofcopiesxCostper1000
copiesofONEcolour.
=2x4000x900(ink,labourandoverheads)
=Rs.7200/-…………………...…………Cost D
Cutting,finishingandfolding:Rs.1000/-…...…Cost E
Cost=A+B+C+D+E=Rs.14,630/-
TOTAL=Cost+10%=Rs.16,093/-
Costperposter=TOTAL/4000=Rs.4/-
31i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Case2: Offset printing Book
No.ofcolours(cover):2+0colour
No.ofcolours(inside):1+1colour
No.ofcopies:200nos.
No.ofpages:48
Paper1(cover):Size+Weight
Paper2(inside):Size+Weight
Finishedbooksize:lxhcm
Papercost(inside):
Opensize/sizeofspread=2bxl
6spreads/sheet
12pages/plate
24pages/sheet.
No.ofsheets/book
=No.ofpages/24
=2No.ofsheetsxno.ofcopies
=2x200=
400+10%test
=440nos.
Totalno.ofreams=No.ofsheets/500=1
ream
Costofpaper2=Cost/reamx1ream=
Rs.800/-………………..Cost A
Papercost(cover):No.ofcopies=440
No.ofsheetsofpaper1=No.ofcopies/No.of
coverspersheet=200/3=66nos.
Artpaper/100sheets=Rs.300/-
Costofpaper1=500xno.ofpackets=
Rs.500/-……………….Cost B
Plate:No.ofplates=No.ofinsideplate+No.
ofcoverplate
Platecostforinsidepages=No.ofinsideplatex
Costforinsideplate……….....Cost C
Platecostforcoverpages=No.ofcoverplates
xCostofcoverplate…………Cost D
Processing
(Imagesetting/positivemaking):No.of
positives=No.ofpages/2=24+cover
Cost=No.ofpositivesxcostperpositive
……………..Cost E
Printing:
Insidepages:
No.ofplatesxno.ofcopiesxcostof1000/
colour
Coverpage:
No.ofplatesxno.ofcopiesxcostof1000per
2colour........................Cost F
Post-press:Costpercopy
Cost=A+B+C+D+E+F
TOTAL=COST+15%
32 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Relief PrintingA relief print is an image created by a printmaking
process where protruding surface faces of the plate is
inked; recessed areas are ink free. It is the oldest known
method of printing.
Letterpress printing
Itissformofreliefprintingoftextand
imageusingapresswithaprintingpress
andmovabletype,inwhichareversed,
raisedsurfaceisinkedandthenpressedinto
asheetofpapertoobtainapositiveright-
readingimage.Itwasthenormalformof
printingtextfromitsinventionbyJohannes
Gutenberginthemid-15thcenturyuntil
the19thcentury.Itisaprocessbywhich
manycopiesofanimagecanbeproducedby
repeateddirectimpresionofaninkedraised
surfacetoacontinuosrollofpaper.
Letterpressprintingexertsvariableamounts
ofpressureonthesubstratedependingon
sizeandimageelements.Chemicalusedin
letterpressarefilmdevelopers,inks,blankets
androllerwashes.Itusesinkwithathick
consistency.
Press methods
Rotary press-Theplateismountedontoa
cylinderwherearollersystemappliesinkto
theraisedareaoftheplate.Thepaperpasses
betweentheplatecylinderandanimpression
cylinderwheretheresultingsqueezebetween
thetwocylindersproducestheprinted
impressiononpaper.
33i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Flatbed Cylinder press -Thetypeorplate
islockedintoachasethatisthenmounted
onthepressflatbed.Grippersonarotating
impressioncylinderpickupasheetofpaper
itispulledaroundthecylinderasitrevolves.
Theinkedflatbedwiththeletterpress
platethenmovesunderthecylinder.The
compressionbetweentheimpressioncylinder
andtheflatbedcreatestheprintedimageon
paper.Whentheimpressioniscompletethe
flatbedreturnstoitsoriginalpositionandis
inkedforthenextimpression.
Platen Press -Movablemetaltypeislockedinto
aframecalledachase,whichisthenplacedin
thepressbedandlockedintoposition.During
theprintingprocess,grippersmovepaper
sheetsfromthefeedboardtotheplaten,which
isthesurfacewheretheprintimpressionis
made.Asetofrollersappliesinktothetype
onthepressbed,thenthepressbedandplaten
arepressedtogethertoproducetheimageon
paper.Whentheimpressioniscomplete,the
platenandpressbedspreadapartandthe
grippersremovethepapertoadeliverytray.
Printingandnon-printingareasarehence
separatedmechanically.
Identification
Uponcloseexamination,letterpress
printwillrevealthefollowing:
1.Inksquashesonedges
2.Minorindentationofpaperonthe
back.
3.Highinkintensity
Application
Letterpresswasextensivelyusedbuthas
nowbeenreplacedinmostapplications
byflexography.Itisusedforpublishing
newspapers,labelsorpackagingtext.
However,amorecommonapplicationo
thistechnologyisfordecorativeeffects
likeembossing,die-cutting,numbering,
perforatingandfoilstamping.
34 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Flexography
Thereliefplateusedforflexographyismadeof
mouldedrubberorphotopolymermaterialswith
theimagearearaisedandthenon-imagearea
recessed.Flexographicplatescanbecreated
withanaloganddigitalplatemakingprocess.
Flexographyisadirectprintingmethodinthat
theinkplateappliesdirectlytothesubstrate.An
inkrollerknownasan‘Aniloxroller’,appliesink
totheraisedportionsoftheplatewhichisthen
transferredtothesubstrate.Theanilinroller
hascellsthatcarryaspecificamountofinkto
theplate.Thenumberofcellsperlinearinch
canvaryaccordingtothetypeofprintjoband
thequalityrequired.
Thenameanilinisderivedfromtheinkthat
wasusedfrotheprocessuntil1950.Theink
carryingrollerhascontinuedtobecalledthe
anilinrollereventhoughtheanilinedyeinks
arenolongerusedforflexography.Thecurrent
inksareveryfluidanddryrapidlyandare
mostoftenwaterbased.It’squalityhoweveris
notashigh.Theinkisfastdryingwhichisan
advantage.
Application
Flexographycontinuestobethefastestgrowing
printprocessesandisnolongerreservedjustfro
printingspecialtyitems.Theabilitytoprinton
avarietyofsubstratesallowstheprocesstobe
usedonawiderangeofprintedproducts.Food
packagingisanimportantmarketbecauseof
theabilityofflexographytoprintonnon-porous
substances.Thisabilityisusefulfroprintingon
plasticbags.giftwrap,wallcovering,paperback
books,telephonedirectoriesandbusinessforms.
35i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Offset Printing Nearly 40% of all print jobs are done by of fset printing.
It is an indirect printing process which means that the
image is transferred or of fset from one surface to another.
Principle
Itisbasedontheprinciplethatoilandwaterdo
notmix.Theimageareaandthenon-imagearea
oftheoffsetplateareonthesameplaneanddo
notmix.Thenon-imageareasoftheplateattract
awettingagentandrepelinkmadefromoilbase.
Theimageareasattracttheinkandrepelthe
fountainsolution.Hence,theseparationisdone
chemically.Thisprocessiscalled“offset”because
theimageisn’ttransferreddirectlyfromplateto
paper,buttoablanketfirstbeforefinallyprinting.
Becauseoffsetprintingdoesnotallowforvariable
repeatsinonemachine,offsetpressesarebestused
inhighvolumeapplicationssuchastheprintingof
newspapers.
Plate production
Firstthepositiveisprintedonatransparency.
Thistransparencyisplacedfront-side-downonto
apresensitizedplateleavinggrippermargins
presetbythemachineandmarkingthecentre.
Itisthenexposedwherebythenegativespaceis
hardened.Theplateisthenwashedwithaalkali
developer(Novatone)diluted300g/L.Hence,the
plateismadereadyforprinting.
36 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Process
Theprintingplateismountedonacylinder
thattransferstheimagetoarubberblanket
mountedonanothercylinder.Theimageis
thentransferredfromtheblanketcylinderto
thesubstrateasthesubstratepassesbetween
theblanketcylinderandimpressioncylinder.
Whentheimageistransferredtotheprinting
surfaceitbecomesright-readingagain.Types
ofoffsetpress
Web fed:Awebfedpressprintsona
continuoswebofpaperfedintothepressfrom
alargerollofpaper.Thewebofpaperisthen
cutintoindividualsheetsafterprintingor
sometimesleftperforated.
Sheet fed:Asheetfedpressprintsimage
onsinglesheetsofpaperastheyarefed
individuallyintothepress.Theprintquality
andsheettosheetregistrationisoftenbettter
thanweb-fedprintingbutitisoftenmore
economicaltoproduceverylargerunsonweb
pressesbecauseoftheirhighspeed.
Waterless Printing :Offsetprintingcan
bemademoreenvironmentallyfriendlyby
removingwaterfromtheprintingprocess.
Thewaterlessprocessusesthelithographic
(offset)systemwhileeliminatingthefountain
solution,ordampeningsystem.Insteadof
conventionalmetal,paperorplasticprinting
plates,waterlessoffsetprintingusesamulti-
layeredsiliconecoveredplateandspecialink.
37i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Thisprocessstillprovideshighqualityand
efficiencywithlowdotgainforenhanced
detail,bettercolorsaturationandfaster
makereadies.Withoutadampeningsystem,
waterlessprintingrequirestemperature
controlsfortheinkrollersandmorefrequent
cleaningoftheblankets.Theplatechemistry
issolventbasedandrequiresspecialhandling.
Becauseofthesolventsused,inksinwaterless
printinghaveahigherVOCcontentthanthe
onesusedinconventionallithography.
Identification
1.Evenimageintextandhalftone
2.Sharpandclearoutline
3.Solidcolorsaregood.
4.Goodtextreproduction.
Application
Thetypesofprintedmaterialsthatcanbe
producedwithoffsetarenumerousandvaried.
Newspapers,books,magazines,businessforms,
advertisingpieces,brochures,posters,greeting
cards,businesscards,mailers,couponsetc.
38 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Gravure PrintingGravure is a high quality printing process capable of
producing printed images which have a continuos tone
ef fect similar to a photograph.
Theimageareaconsistsofhoneycombed
shapedcellsorwellsthatareetchedontothe
surfaceofacoppercylinder.Theunetched
arearepresentsthenon-printingarea.The
cylinderrotatesinabathofinkcalledtheink
pan.Asthecylinderturns,theexcessinkis
wipedofthecylinderbyaflexiblesteeldoctor
blade.Theinkremainingintherecessedcells
formstheimagebydirectransomertothe
substrateasitpassesbetweentheplatecylinder
andtheimpressioncylinder.
Themajorunitoperationsingravureprinting
areasfollows:
Image preparation
Cylinder preparation
Printing
Finishing
Besidesbeingveryfluidandthin,theinksused
withotherprocesscolourapplicationsdifferin
huethantheinksusedwithotherprocesses.
Gravurealsooftenemploysspotcolourinks
insteadofthestandardprocesscoloursusedin
four-colourprinting.
Gravureisadirectprintingmethodsothere
isnoneedtoutilizefountainsolutiontokeep
thenon-imageareasclean.Printedimageswith
gravureareofthehighestqualitybecausethe
39i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
thousandofinkcellsappeartomergetogether
toformacontinuostone.Howevertheclarity
oftypeinsmallerpointsizesisnotasgoodas
offsetlithography.
Application
Gravureisusedtoprintverylargequantity
ofunto10-15millioncopies.Itisusedto
printpackagingapplications,magazinesand
pressuresensitiveapplications.TheNational
Geographicmagazine,agloballycirculated
magazinethatisfamousforit’ssuperior
photographyusesgravureprinting.Itisalso
usedforitemslikecurrencynotes,stampsand
foils.
Conventional gravure cells have
equal area but dif ferent depth.
Deeper cells hold more ink and
make darker impressions.
Cells with dif fering area
and equal depth are used for
packaging applications.
Cells with variable area and
variable depth are used for high
quality applications.
40 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Screen PrintingIt is arguably the most versatile of all printing processes.
It can be used to print on a wide variety of substrates.
Screen making
Astencilisproducedonthescreen.Thisisdone
byfirstdensifyingthetransparencypositive
withasolutioncontainingpolyvinylalcoholand
ammoniumbichromate.Thepositiveisplacedon
thescreenmeshandthencoatedwithSonakote
solutionandLunarsensitizersolution.Itisthen
placeddownonalighttableandcoveredwith
sandforkeepingtightcontact.Theexposure
lastsforapproximately8minutes.Theexposed
negativespacecoveredbythesolutionhardens
andbecomesimporoustoink.Themeshis
stretchedtightlyoveraframemadeofmetalor
wood.
Printing
Screenprintinginkisthenappliedtothe
substratebyplacingthescreenoverthematerial.
Inkwithapaintlikeconsistencyisplacedover
thescreen.Inkisthenforcedthroughthepositive
openingsusingasqueegeethatisdrawnacross
thescreenfromtoptobottom.Inkonlypasses
throughtheunexposedportionthusformingan
imageonthesubstrate.
Thediameterofthethreadsandthethreadcount
(basicallythelip)willdeterminehowmuchinkis
deposited.
41i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Advantages
Theadvantageofscreenprintingoverother
processesisthatitcanprintonmaterialof
differentshapes,materialsandsize.The
equipmentcostforscreenprintingarelessthan
thatofotherprocessesbutrateofproduction
isslower.Theyarehencesuitableforsmaller
quantitiesofprints.
Identification
1.Slightlyraisedimpressionduetoheavy
depositionofink
2.Highandeveninkdensity
3.Textisblurredcomparedtooffset.
Applications
Productsasvariedassigns,posters,circuit
boards,mugs,clothingandsoftdrinkbottles
canbeprintedusingthisprocess.Screen
printingisveryusefulwhenaninaneneeds
tobewrappedaroundanobjectorwhenthey
needtobefitontooddlyshapedobjects.
42 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Unconventional PrintingThe processes discussed earlier are called conventional
processes. They all required a master plate and were
printed in large quantities. Unconventional processes are
those in which there is no master, no impact press and
more economical for very small quantities.
Thereproductionofdigitalimagesonregular
paper,photographicpaper,andotherprintable
surfaces.DigitalPrintingdiffersfromoffset
printinginthattheinkdoesnotabsorbintothe
paper,asdoesconventionalink,butformsalayer
onthesurface.Itrequireslesswasteintermsof
chemicalsusedandthepaperwastedduringthe
setupprocess.
Mostdigitalsystemsdoawaywiththefilm,plates
andinkthatarepartofoffsetprintinginfavor
ofsomesortofelectrophotographicprocess.
Particlesofdryorliquidtonerareattractedto
anelectrostaticallychargedcylinderthatcarries
theimage.Thetoneristhentransferredtothe
paperor,lessoften,toablanketcylinderandheat
isusedtomeltandsetitonthepaper.Digital
inkjetpressesuseanelectricalchargetoguide
theplacementoftinydropsofinktocreatea
glossyimagethatcanrivalacontinuous-tone
photograph.Hybridtechnologiescombinedigital
andconventionaloffsettechnology.
DigitalPrintingisusedprimarilyforsmall
quantity,short-runprintingandvariabledata
printingjobsthatrequireaquickturnaround.
Thisoptionisacost-effectivemethodforFull
ColororB&Wbooklets,businesscards,catalogs,
magazines,manualsormulti-pagebrochures.
Booksandbrochurescanbeprintedon-demand
43i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
astheyareordered,eliminatingtheneedto
holdlargequantitiesininventory.
Advantages
1.Digitalprintingisfastandflexiblebecause
there’snoseparateproofing,nofilmorplates,
andlittlemake-readytimeisneeded.
2.Digitalisverycost-effectiveforsmallruns.
3.Digitaltechnologyisconstantlyevolving.
Newadvancesarebeingmadeinareassuch
asin-linevarnishes,scratch-proofinksand
finishingtechniques.
4.Digitalprintingcanvarytextandimages
onapage-by-pagebasis,allowingfor
customization.
5.Chemicalsassociatedwithfilmprocessing
andplatemakingareeliminatedmaking
digitalmoreenvironmentallyfriendly
6.Electrinksystemsusedindigitalprinting
havelessemissions
Methods
Thermography
Thisisaprocesswhichproducesaglossy,
raisedimagebyusinginfraredlight.The
imageisfirstprintedbyletterpressorlitho
usinganadhesiveinkwhichiscoatedwitha
fusibleresincontainingpigmentonametallic
powder.Whenpassedunderlighttheresin
pigmenthardenstogiveahardraisedimage.
Thermographicpowdersaremadefromplastic
resinswhichwereintroducedinthe1970’s.
Theyhavetakentheplaceoftraditionally
manufacturedwithabasemadefrom
groundtreesap.Thereareawiderangeof
thermographicpowdersthatarecapable
ofproducingawedrangeofeffects.The
powderscomeinmanyparticlesizes.
Itcanaddvaluetomanyordinaryprint
applications.Letterheads,greetingcards,
invitations,businesscards,marketing
applicationsandenvelopes.
Thermographyprintingcangenerally
onlybeusedononesideofthepaper,as
applyingthenecessaryheattothesecond
sidewouldnegativelyaffectthefirstside.
Thermographyshouldnotbeusedovera
foldorwithinaonefourthofaninchfrom
theedgesofthepaper,astheraisedink
tendstofracturewhenfoldedorcut.
44 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Ionography
Aprocessthatmakesuseofanimagewitthe
useofanelectroncartridgewhichcreatesa
negativechargeonanonconductivesurface.
Thenonconductivesurfaceattractsa
magnetictoner.Astaticelectricchargeisused
todrawtheparticlesfromthedrumontothe
substrate.Ahighpressurerollerfusesthetoner
tothesubstrate.
Magnetography
Itissimilartoiconographyexceptthatthe
drumusedismagnetic.Theelectronicimage
isconvertedtoamagneticdrumchargewhich
attractsatonercontainingironparticles.The
tonersareveryopaquesotheprocessisbest
suitedforspotcoloursratherthanprocess
coloursthatrequiretransparentcoloursto
workproperly.Magnetographyisusedfor
applicationswhichrequirevariableimaging
suchaslabels,businessforms,directmail
pieces,ticketsandbarcoding.
Electrography/Xerography
InventedbyChesterCarlsonin1937and
developedbyXeroxCorporation.Artwork
isplacedfacedownonaglassplateandis
illuminatedbyafluorescentlightwhichtravels
thelengthoftheimage.Thereflectedimage
isdirectedthroughthelinesthroughthelens
toanelectricallychargeddrum.Thischarge
leaksawaywherelightfromtheimagefallson
thedrum.Aresinbasedpowdercalledtoneris
transferredtoasheetofpaperwhereitisfixed
45i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
byheat.Lasercopiersworklikecombined
scannersandimagesettersbyscanningthe
imagedigitallyandusingalasertowritethe
imageontoanelectrostaticdrum.
Inkjet
Aninkjetprinterisanyprinterthatplaces
extremelysmalldropletsofinkontopaperto
createanimage.
Identif ication:
1.Thedotsareextremelysmall(usually
between50and60micronsindiameter),so
smallthattheyaretinierthanthediameterof
ahumanhair(70microns)!
2.Thedotsarepositionedveryprecisely,with
resolutionsofupto1440x720dpi.
3.Thedotscanhavedifferentcolorscombined
togethertocreatephoto-qualityimages.
In unconventional printing, because
there is no single master an independent
image is generated on the cylinder for
each individual print. Hence, the per
cost copy remains the same irrespective
of quantity.
46 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Post PressPostPress is a crucial part of any printing process even
though it takes place after the actual printing, since it
determines the f inal look, shape and feel of your printed
product.
UV coating
UVcoatingprovidesthefinalglazeontheprinted
materialandprovidesfinelustrouseffecttothe
finalproduct.Ourmachinescanalsodeliver
SpotUVeffectwhereinonlyspecificpartsof
theprintedmaterialarecoatedtohighlighta
particulardesign,fontorcolour.
Advantages
Opacity
Stability
Ecofriendly/nonVOC
Highgloss
Sharpgraphic
Chemicalresisting
Scuffresistance
Deeperandmorevibrant
Die-cutcapable.
Lamination
Laminationfinishingtechniqueissimilarto
varnish,butitdeliversmoreshineandprovidesa
richerappearancethanvarnish.TheLamination
effectworksverywellforsophisticatedpackaging
requirementssuchascosmeticandperfume
packages,invitationcardsanddesignerbrochures.
47i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Die Punching
TheHiedelbergCylinder,PolarMohr
Eltromatetcfordifferentcuttingrequirements
likediepunching,cutting,creasingetc.Apart
fromcuttingandpunching,diepunching
machinescanalsogivecreasedandEmbossed
effects.
Folding
AutomaticInsertFoldingMachines
automaticallyfoldsanytypeofpaperinto
differentfoldingpatterns,primarilyuseful
formedicalinserts,notebooks,textbooks,
magazines,brochures,etc.
Foil Stamping
Foilstampingprovidesarich,shining,metallic
effectonprintedmaterialandpaper.Machines
likeKlugeEHDthroughwhichfoilisstamped
inanydesiredshape,fontanddesignonthe
printingmaterialorpackage.Thisisvery
usefulinweddinginvitations,perfumeand
cosmeticpackages,FMCGpackagingetc.
Embossing
Embossingisanotherdesigneffectthatcanbe
createdthroughmachines,givingtheeffectof
raisedordeepimpressioninanypresetdesign.
48 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
BindingBindingisaprocessoffasteningthesheetsofa
publicationintheproperorderandmostoften
withaprotectivecover.
Sometypesofbinding:
Plastic comb binding
AlsocalledGBCbinding,plasticcomb
bindingispunchandbindsystemthatisused
formanyofficedocuments.Itsmainadvantage
isthatitisinexpensiveandeasilyedited.It’s
advantageisit’sappearanceandthesecurity
ofthefinalbook.Also,likeotherpunchand
bindsystems,itrequiresmorelabourthantape
binding.
Spiral Binding
Itisapunchandbindsystemthatusesa
plasticormetalspiralwirethatiswound
throughpunchedholesonbindingedge.Itis
thetypeofbindingmostoftenusedforschool
notebooksandstenopads.
Perfect binding
Itisapunchlessbindingmethodthatworks
byfasteningthebookblocktothecoverspine.
Itisoftenusedforsoftcoverbooksandpaper
backs.
Tape binding
Thisprocessplacesaclothstripofadhesive
tapedownthebindedgeofthebookand
wrapsaroundabouthalfaninchontothe
coverandback.
49i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Saddle stitch
Wirestaplesholdthepiecetogether.A
machinedrivesthenthroughit’sbackbonefold
tothecenterfoldwheretheyclench.
Side stitch
Thepagesarecutallthesamesizeand
stacked,thenstaplesareinserteddowntheside
ofoneedgeofthebook’sfront,2to3times
dependingonthicknessandpaperweight.The
resultisasturdybinding,howeverthebook
willnotlieflatwhenopened.Thisbinding
styleisgenerallylessexpressivethanother
styles.Ithastypicalusesinnotepads,reports
andtear-offcalendars.
Case Bound (Section sewing)
Thisbindingstyleistypicallyusedforbooks
ofmorethan80pages,whichrequireastrong,
high-qualityfinish.Thepagesofthebookare
collated,andthensewntogetherwiththread.
Thecoveristhengluedtothespineofthe
pageblock.CaseBoundisgenerallythemost
expensivestyle,soareusuallyonlyusedfor
booksthatmustwithstandconstantuse.
It’susedforhardcoverbooks,textbook,novels.
Wire-O-binding
Thisbindingholdsthepagesofthebookin
placebyadouble-loopwireinsertedthrough
holesontheleftedge.Itdoesnotspiral
throughthebookratheritcreatesawirecomb.
Thepageslayflatwhenopenedandcanrotate
360degree.Wire-Obindingsaredurable,but
donotpermitprintingonthespine.Itisused
inreferencebooks,reports,cookboooks.
50 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
Field VisitWevisitedtwoprintingpressesduringourcourse.
Hereweobservedcommercialscaleprinting,die-
cuttingandpackaging.Wesawtheprocessofoffset
printingandprocedureofit’splatemaking.The
presshadfourandfivecolourprintingsheet-fedoffset
machines.UVprintingwasalsocarriedout.Wealso
observedmedicinepackagingfromfoldingtosealing.
Thesecondpartofourtripwasavisittocorrugated
paperfactorywheresinglesheetsarepassedthrough
corrugatingmachinestoforma‘ply’.Theseindividual
plyarethenlayeredonetopofeachothertoform
multiplycorrugatedsheetsofgreaterstrength.They
werethendie-cut,foldedandstapledintoboxes.
Onthesecondvisit,wewitnessedexecutionofa
calendarandschooltextbookfromstarttofinish.
Thiswasaveryvaluableexperienceaswewereable
toseethepressworkflowinpractice.8-pagesignature
imposedbookprinting,gatheringandside-stitchbind
wasdonethere.
51i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
52 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
PracticalAttheNIDPrintingLabwegainedpractical
knowledgeintwomethodsofprintingnamelyoffset
andscreen.Foroffsetprinting,wefirstcreatedan
artworkofapproximately11”x8”.Theaimwasto
testoffsetprintingbyexperimentingwithextreme
pointsizesandcolourmediumsandtones.Inscreen
printing,theartworkwasprintedonavarietyofplane
surfacematerialstestingitscapacitytoreproduce
onpaper,plasticandmetalsheetswithavarietyof
textures.Onthesetwodays,wehadastepbystep
understandingoftheprocessfollowedinexecution
oftheprint.Iwassensitizedtotheextremecareand
precisionrequiredinprinting.Theeffortrequiredto
attainevenasinglecolouroffsetprintwasconsiderable.
Loadingtheplate,cleaningtherolllers,dampening
andtestrunsweresomeofthestepsweparticipatedin
duringthesesessions.Wealsohadtutorialsinbook
bindingtechniques.Wecoverednotepadbinding,
pefectbinding,spiralbinding,japanesebindingand
librarybinding.Itwasvaluablebecauseweunderstood
thereasonsbehindimpositionmethodsandwhatwe
requiretobeawareofwhiledesigningadocumentso
thatit’sbindingandfinishingcanbedonewell.
53i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
54 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
References
Coursenotes
ProcessofGraphicProductioninPrinting,Curwen
PrintingEffects,WayneRobinson
GuidetoPrinting,WilliamCloves
AGuidetoPrintProduction,JohanssonLundberg
Ryberg
www.pneac.org
www.internationalpaper.com
www.paperrep.com
www.heidelberg.com
www.agfa.org
www.wikipedia.org
www.brittanica.org
GoogleImagesearch
DocumentsetinBaskerville/FontFolio09
55i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
BharatSuthar
Dr.TridhaGajjar
NIDPrintingLab
Acknowledgments
56 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
57i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
58 i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
C0 1000 x 1414 mm
B0 917 x 1297 mm
A0 841 x 1189 mm
59i n t ro d u c t i o n to p r i n t i n g t e c h n o lo g y
A0 841 x 1189 mm
A1 594 x 841 mm
A2 420 x 594 mm
A3 297 x 420 mm
A4 210 x 297 mm
A1
A2 A3
A4