the book of printing technology

AsminA shAikhsemester 4 | grAphic design

introduction to printing technology

contents history of printing

methods of pring

conventional methods

Unconventional methods

the printing process

types of originals

colour and printing

scanners

imposition

paper

post press oprations

Binding

costing and estimation

Field visits and practicals

Bibliography


the Babylonians used a technology in which seals were pressed into damp

clay but the chinese probably invented the printing technology.they used

carved stones for making copies by first sprinkling soot over them and then

pressing a paper on it and rubbing it until the ashes came off the stone.

the oldest known prints were produced in china about 1200 years ago.they

consisted of Buddhist texts and were made using ink blocks and small pieces

of paper.

history of printing


Around 800 years ago a Chinese printer Pi Sheng first formed Chinese

characters out of bits of clay. the small pieces could be reused and were

similar to what we now call ‘movable type’. Later type was made out of

wood.

stencils was another ancient method of printing. the technique reached

its peak in katazome used on silks for clothes during the edo period in

Japan. most common uses of stencils was to colour old master prints

printed in black and white, usually woodcuts. it was also used to colour

playing cards.


the conventional methods of printing need a master to mass produce

multiple copies of the original. the following methods are considered as

conventional:

+ relief printing

+ Lithography

+ intaglio

+ screen printing

methods of printing conventional methods of printing


platen press

A platen press is made up of two flat surfaces called the bed and the platen.

the platen provides a smooth backing for the paper or other substrate that

is to be printed. The raised plate (image to be printed) is locked onto a flat

surface. The plate is inked, the substrate is then placed on another flat surface

called the bed and pressed against the inked plate producing the impression.

relief printing

A relief print ia an image created by a print making

process where a protruding surface faces the matrix

(printing plate or block) are inked, recessed areas are ink

free. paper ia pressed aginst the matrixx and ink from

the protruding surfaces is transfered to the paper. relief

printing uses three kinds of presses.


the platen and bed carry both the paper and the type form. the

press then opens and closes like a clam shell. platen printing

is typically used for short runs such as invitations, name cards,

and stationary. Larger platen presses are used for die-cutting

and embossing. some platen presses are arranged with the bed

and platen in the vertical plane.

the plate is inked with an inking roller that transfers ink from

an inking plate to the image carrier. ink is placed on the inking

plate by an ink fountain roller. the platen style press has been

widely used in printing small-town newspapers since the late

1800s. the printing area is usually limited to a maximum of

18 inches by 24 inches. these presses are also used to print

letterhead, billheads, forms, posters, announcements, and

many other types of printed products, as well as for imprinting,

embossing, and hot-leaf stamping.


flatbed cylinder press Flat-bed cylinder presses use either vertical or horizontal

beds. the plate is locked to a bed which passes over an

inking roller and then against the substrate. the substrate

passes around an impression cylinder on its way from the

feed stack to the delivery stack.

Another way of describing this is that a single revolution of

the cylinder moves over the bed while in a vertical position

so that both the bed holding the substrate and cylinder

move up and down in a reciprocating motion. ink is supplied

to the plate cylinder by an inking roller and an ink fountain.

the presses can print either one or two-color impressions.


Flat-bed cylinder presses, which operate in a manner similar to the

platen press, will print stock as large as 42 inches by 56 inches. Flat-bed

cylinder presses operate very slowly, having a production rate of not

more than 5,000 impressions per hour. As a result, much of the printing

formerly done on this type of press is now done using rotary letterpress

or lithography.


rotary press

the rotary press is a printing press in which impressions are

curved aound a cylinder so that the printing can be done on long

continuous rolls of paper. rotary drum printing was invented by

richard mar ch hoe in 1847 and was improvd by william bullock in

1863. there are two types of rotary letterpresses, sheet-fed and

web-fed.

Web-fed rotary letterpress presses are used primarily for printing

newspapers. these presses are designed to print both sides of

the web simultaneously. typically, they can print up to four pages

across the web; however, some of the new presses can print up to

six pages across a 90-inch web. rotary letterpress is also used for

long-run commercial, packaging, book, and magazine printing.

sheetfed rotary presses are also declining in use; in fact these

sheetfed rotary presses are no longer manufactured.


letterpress

Letterpress printing is relief printing of text or image using a press

with a ‘type high bed’ printing press and movable type in which a

reversed raised surfce is inkedand then pressed into the papaer t

obtain a positive right reading print.

The first movable type was made in china bu bi sheng out of

porcelian in 1040.The first metak movable type was invented

in korea in 1230 and in 1439 johannes guttenburg developed

european movable type printing. By trial and error guttenburg

discovered that an alloy of lead, tin and antimony was the best

combination to produce movable types as it did not shrink on

cooling.

methods of relief printing


guttenburg is also creadited for the use of oil based inks which was more durable

than previously used water based inks which would be dried by oxidation and

penetration.The first book he printed using movab;e types was guttenburg’s bible

published in 1456 which is 1282 pages long.the biggest advantage of movable type

was that it could be used over and over again.

pre press prodUction

Letterpress uses type that is raised from the non

printing which is achieved by using movable metal

type casted in metal(alloy of antimony,tin and lead).

the non printing areas are sunken.in traditional

letterpress work, letters were assembled into copy

and line drawings were etched or engraved into

plates and all this was placed or composed on a flat

marble stone or within a rigid frame spaced with

blocks,tightned up and locked.


typesetting

typesetting in itself was a skill and intially done

manually. typesetting operations assemble the

type characters into pages. there are a number of

methods of typesetting including manual assembly

of pieces of metal type (letterpress), mechanical

assembly of lines of type, and phototypesetting.Until

the 1950s, the majority of typesetting was performed

using the linotype machine which produces a

“slug” or line of type from molten metal. similar

machines produced single characters of type. today

phototypesetting devices have almost completely

replaced manual and mechanical methods of

typesetting.


Phototypesetting devices, first demonstrated in the late

nineteenth century, were introduced commercially in

the early 1950s. they rapidly overtook the linotype and

similar machines in importance. in phototypesetting,

individual type characters or symbols are exposed

onto photographic film or paper. In early mechanical

phototypesetting units, entire fonts of characters were

stored as negatives on film. In the later generations

of computer-driven phototypesetters, the image is

generated electronically, and, in the latest generation

of units, a laser is used to project the image onto the

photographic film or paper. Phototypesetting produces

high contrast, high resolution images ideal for printing

purposes.


flexography

Also known as surface printing flexography is most commonly used for

packaging. it is achieved by creating a mirroed master of the required image

as a 3d relief in rubber or polymer material. then measured amount of ink is

deposited on the surface of the plate using anilox roll and the print surface

is rotated and the ink is transfered o the paper.Fast drying inks which are

highly volatile are used in flexography.


lithography

Lithography was invented in 1976. it is a method of printing on smooth

surfaces. it uses a chemical process to create an image. the positive of

image id hydrophobic, hence when the plate is introduced to an ink and

water mixture, ink adheres to the positive of the image and is tranfered

to paper when pressed against paper.

offset lithography

this method of printing depends on photographic process and uses

a flexible aluminium or polyester plates. The plates have a rough

textured surface and are covered by phoosensitive emulsion.A

photographic negative of te desired image is placed in contact

with the emulsion and the plate is exposed to ultraviolet light. After

development a reverse negative (positive) is obtained.


intaglio

this method was invented in germany in 1436.A family

of print making in which the image is incised into a

surface known as aa matrix or a plate.in this method the

printing areas are the sunken and non printing areas are

raised.normally copper or zinc plates are used. incisions

are created by etching, engraving, drypoint,aquatint or

mezzotint. in intaglio printing the plate is covered with

thick layer of ink and te excess is wiped out leaving ink

only in incisions. A damp paper is placed on top and then

the paper and plate are run through the press , through

pressure recesses of t the ink transfers from the recesses

of the plate on paper. this method is used for very high

quantities (10-15 million copies) and very high quality

printing.this method is not considered for printing text

as it gives jaggered edges.


screen printing

screen printing has its origins in simple stenciling , most notably of the japanese form ( katazome) which

used cut banana leaves and inserted ink through the design holes on textiles. modern screen printing process

originated from patents taken out by samuel simon in 1907 in england. nylon, polyester and wire meshes are

used to make the matrix.more the number of threads per inch sharper the image.this method can be used to

print on any surface and has maximum ink depth.A light sensitive liquid consisting of a mixture of ammonium

bichromate and pva( polyvinyl alcohol).ythis method can be used to make upto a 100 copies at a time.


collotypethis method is a planographic process which uses photographic gelatin.

this method is used to obtain very high quality black and white or colour

continuous tone prints without the use of a screen.

thermographythis method produces glossy raised images by using

infrared light.First printed by letterpress using transparent

adhesive ink coated with resin and passed under infrared

light.


die stampingthis method gives a raised blind embossed image.

foil stampingin this method a heated block presses the foil on the paper.

Under pressure the foil is cut and pasted on the paper.


Also known as non impact printing these methods donot need masters to

produce multiple copies of the original.they are essentially non conntact

processes. it produces a new image everytime for every print. common non

impact printing methods are electrophotography, inkjet printing, thermal

images, laser printing,etc.

unconventional methods of printing

electrophotography

Also known as electrostatic printing , this technology was

invented by chester carton in 1937 at the xerox corporation.

It is based on a modified xerographic copier. In this the

image is illuminated by a flouroscent light and the reflected

image is directed through te lenses on to a electronically

charged drum. A resin based powder called the toner is

attracted to the image areas and ia transfered to sheets of

paper and is fixed (fused) by heat.


inkJet printing

ink-jet technology creates printed documents

with streams of ink drops that are deflected to

the substrate based on information in digital

files. It does not require an image carrier, or

plate, and it does not required equipment like a

xerographic device or a printing press. the same

information can be printed throughout a print

job or variable information can be printed based

on the requirements of the application. the main

types of ink-jet technologies are continuous jet

and drop-on-demand.


continuous jet

With continuous jet technology, drops of ink are continuously produced

and applied to the substrate to produce the image. A pump sends ink drops

through a nozzle at the rate of over a million per second which can produce

an image of nearly the same quality as a continuous tone image such as a

photograph. there are three types of continuous jet technologies: charged

drops for printing, uncharged drops for printing, and electronic deflection.

drop-on-demand

drop-on-demand is a type of ink-jet technology in which the ink drops are

formed and then applied as a response to a digital signal. there are two

types of drop-on-demand printer systems: piezoelectric and thermal ink-jet.


laser printing

A laser printer is a common type of computer printer

that rapidly produces high quality text and graphics

on plain paper. Laser printers employ a xerographic

printing process but differ from analog photocopiers

in that the image is produced by the direct scanning

of a laser beam across the printer’s photoreceptor.

the laser printer was invented at xerox in 1969 by

researcher gary starkweather. A laser beam projects

an image of the page to be printed onto an electrically

charged rotating drum coated with selenium or, more

common in modern printers, organic photoconductors.

photoconductivity removes charge from the areas

exposed to light. dry ink (toner) particles are then

electrostatically picked up by the drum’s charged areas.

the drum then prints the image onto paper by direct

contact and heat, which fuses the ink to the paper.


ionography

ionography is also known as "ion deposition"

or electron "charge deposition printing". the

ionographic process creates an image with the

use of an electron cartridge which creates a

negative charge on a nonconductive surface. the

nonconductive surface consists of a drum with a

dielectric surface of aluminum oxide which attracts

a magnetic toner. The toner is then fixed to the

substrate with a cold fusion process. ionography

uses a static electric charge to draw the toner

particles from the drum onto the substrate. A high

pressure roller fuses the toner to the substrate. A

scraping device removes any excess toner from the

drum and an erasing rod removes the latent image

from the drum so that the drum will be ready for the

next copy.


ionography is used only for one color printing because the high pressure

cold fusion process can slightly distort the substrate, which means that

multiple colors may not line up correctly. it is useful for high volume

applications and for variable information printing, which allows for

changes in the content of the print application during the press run.

Variable applications such as checks, statements, letters, tickets, and

tags, are printed with the ionographic process. Applications printed with

the ionographic process do not hold up to rough handling as well as

applications printed with other processes.


Letterpress+ ink squash at the edge of the letter due to to heavy pressure.

+ slight indentation on the back of the paper.

+ high ink intensity

Offset+ impression will be even on both text and halftone.

+ solid cours are evenly inked.

+ Better text reproduction than gravure. Lines and texts are sharp and

have clear outlines.

hoW to identify?


Gravure+ edges of text will not be sharp.

+ Text is raterised. Lesser quality than offset printing.

+ high image quality.

screen printinG+ heavy ink deposition and a slighty raised impression.

+ high and even ink intensity.

+ Text is blurry and of low quality compared to offset printing.


the printing process for any kind of printing is divided into three basic

steps:

+ pre press

+ press

+ post press

the printing process


pre presspre press operations encompass that series of steps during which the

idea for a printed image is converted into an image carrier such as a

plate ,cylinder or a screen.pre press operations include composition and

typesetting, graphic arts photography, image assembly and image carrier

prepapration.

pressthis refers to the actual process of printing.

post pressthis primarily involves the assembly of printed materials and consists

of basic oprations like folding, cutting, collating, gathering, binding and

packaging.


All offset presses have three basic units of printig cylinnders- the printing

cylinders, the inking cylenders and the dampning unit. the three printng

cylinders consist of the the plate cylinder, the blanket cylinder and the

impression cylinder. Offset lithography uses a planographic plate i.e.

the non printing and the printing areas lie on the same level and are

differentiatd by differing physiochemical properties.

pre press productionBefore the job can be printed, the document must be converted to film

and ‘plates’.Film negatives are created from digital file.Images from the

negatives are transferred to printing plates by a process of exposure with

UV light. every colour needs a plate which means that a seprate plate must

be made for every colour that is printed.


There are four ways to make a plate that is fitted on

the press from the digital files on the computer:

Computer to imagesetter-This method gives a film output and it follows a

process of exposure by uv lights.

Computer to plate (Ctp)-the plate is made by a machine wich uses pre

sensitised plates and exposes the image on the

plate using laser lights.the plate is developed and

dried in the machine itself . An additional coat of

varnish is put on the plate that hardens it and hence

more copies can be printed.


Computer to plate on press-this process uses di technology and the plate is on the press machine

itself . Since this method doesnt not involve fixing the plate on the

machine manually and the plate is exposed after it is fixed on the cylinder

it reduces registration problem.this also is used to print more number of

copies.

Computer to print-this method uses a rechargeable cylinder (similar to the opc drum

in xerox) which creates a new image for every print hence the cost of

printing per copy remains the same. it is a plateless printing process.this

is used for digital offset printing.


Diffrent kinDs Of pLates

diazo plates are coated with organic compounds and are developed with

a special solvent. they have a shelf life of about one year. these are used

for print runs of about 150,000 impressions.

photopolymer plates are coated with organic compounds which are very

inert and abrasion resistant. this makes them last much longer than

diazo plates. they are used for print runs of up to 250,000 impressions

silver halide plates use photosensitive coatings similar to photographic

film, except that the silver halide emulsions are slower and for color

reproduction are coated on anodized aluminum. the processing

solutions contain silver which must be recovered with the proper

equipment before being discharged to the sewer. Film based silver halide

plates are used for single color printing and metal based silver halide

plates are used in computer-to-plate systems.


make reaDy time

This refers to the time that is used to fix plate onto the plate cylinder, set

the ink flow and other parameters to obtain the correct print. Earlier the

process od controlling the ink flow would be done manually but now it is

set automatically. A certain percentage of prints is wasted in this process

and is considered while doing the costing of printing.the press has to

maintain a constant balance between the force required to move the paper

forward and the amount of back pressure thatthe paper allows to remain

tight and flat while printing.All these parameters are set during the make

ready time and are monitered during the rest of the process.


the inkinG prOcess

Offset printing works on the basic principle that water and ink

donot mix.In the process of printing the plate cylinder is first

damped by water (alcohol is now used as it is highly volatile

and gives better result) so that the non printing areas which

are grease resistant absorb water and then it is inked by the

inking unit which is a set of cylinders which pass on the ink from

the ink reservoir to the plate cylinder and the water resistant

areas(printing areas) absorbs ink. the ink from the plate

cylinder is then passed onto to the blanket cylinderthat in turn

transfers the image to the paper.the plate itself doesnt come in

direct contact with the paper thus the term ‘offset’ lithography.

All of this happens at an extremely high speed. After the ink is

transfered to the paper , it is slightly damp and the ink is nt fully

dried. to set the ink on paper it is passed through a drying unit

which dries the paper by either heat or a newer technology uses

a setoff powder that is sprayed on the paper so that ink doesnt

smudge.


line artthis type of artwork contains only black and white pixels. they are also

known as bi-level images.Tey are drawings containing only flat colours

without any tonal values.they are bitmap images with a minimum

required resolution of 1200 dpi.

continous tonethis type consists of the grey scale or colour images.it is considered that

reproduction os glossy pictures is better as they reflect back light into the

scanner evenly. cmyk images have lesser colours and rgb images have

about 1.67 million colours more than cmyk images.

types of originals


halftone

A repographic technique that simulates a continous tone imagery

through the use of equally spaced dots of varying sizes. the idea of

halftone printing originates from William Fox tablot. in the early 1850’s

he suggested the use of photographic screens or veils. the halftone

process reduces visual reproductions to a binary image that is printed

with only one colour of ink. the binary reproductions rely on a basic

optical illusion- that these tiny halftone dots are blended into smooth

tones by the human eye.halftones are used to reduce the amount of

ink on paper. halftone reduces the image to half its size hence before

converting the image to halftone it must be ensured that the original is of

a much higher resolution.

eg. if an image is printed at 150 lpi the scan must be 300 dpi.


screen rulingAlso known as the resolution of the halftone screens, it is measured in lines

per inch (lpi) . this is the number of lines of dots in one inch, measured

parallel with the screen’s angle.the higher the pixel resolution of the source

file, the greater the detail that can be produced. However such an increase

requires a corresponding increase in screen ruling.

density it is the measure of the tonal values of the original or printed image

measured by a densitometer. it is observed that darker the grey value more

is the density.

density rangeAlso known as contrast range it is defined as the difference between the

highest and lowest density in the image.


screen angle the screen angle is another common measurement used in

printing and is measured in degrees, clockwise from a line

running to the left.

multiple screens and color half toning When different screens are combined a number of distracting

visual effects can occur, including edges being overly emphasized,

as well as a moire pattern. this problem can be reduced by rotating

the screens in relations to each other.


traditional screening

the two most common methods of creating screens are :

+ Amplitude modulation

+ Frequency modulation

ampLituDe mODuLatiOnthis produces regular grade of dots that vary in size. the number of dots

per sq unit area remains the same.

frequency mODuLatiOnthis produces an irregular grade of dots that vary in size and number.


aDDitive cOLOurs red, green, blue are considered as additive colours as they combine to give

white light. on the other hand, cyan, magenta, yellow are considered as

subtractive primary colours as together they give black(absence of white

light). hence rgb and cmy are complementary colours.

r + g = y

r + B = m

g + B = c

colour and printing


We see colours as a result of reflection of certain colour of light. Hence, rgb

can’t be controlled in print which is done by cmyk. in 4 colour printing, each

image is broken into single colour layers i.e, cyan, yellow, magenta, black.

the lightness and darkness of colour is altered by the size of the dot in half-

tone as the printer cannot alter the amount of ink. cmyk primary printing

colours cannot produce metalic or flourescent colours. Due to impurities of

inks 100% of all three- cyan, magenta and yellow donot give a 100% black

but a muddy brown. hence a black ink is used to give depth.


colour separation

colour separation is done using primary colour

filters - red, green, blue. Colour seperation is done to

seperate the different layers of colours namely cyan,

magenta, yellow and black. to avoid moire pattern,

the c,m,y and k layers must be at angles such that the

difference is 30 degrees. The below angles form the

rosette patterns.

The difference between yellow and magenta is 15

degrees. But yellow being lighter colour, the moire

pattern is not so visible.


spot colour

In offset printing a spot colour is any colour generated by an ink ( pure or

mixed) that is printed using a single run. While making a miulticolour print

with a spot colour process, every spot colour needs its own lithographic

film.Spot colour printing is usually done using readily available inks.

fake colour

A one colour reproduction printed on a coloured sheet which uses the

colour of the sheet as a second colour.


colour gamut

Colour gamut is defined as the range of colours that

can be viewed, displayed or printed. A certain range

of colours of red, green, blue such as deeper shades

of red, green and blue are beyond the cmyk gamut.

hence, if we choose those while printing, they are

changed to the nearest cmyk colours. hence, rgB

gamut (1.67 million colours) is bigger than cmyk

gamut.


hexachrome

this process was invented in 1994.this method provides a wider

gamut than cmyk.it includes brighter orange, green, purple and

truer skin tones.It is a 6 colour printing process.The file must be in

lab mode/ mode.Also reffered as ‘hi fi’ printing. The inks used for

this method are laser-powder ink, inkjet-liquid ink, digital offset-

powder/liquid.


A scanner is a device that optically scans images, printed text, handwriting,

or an object, and converts it to a digital image.The different types of

scanners are:

+ Flatbed scanner

+ drum scanner

modern scanners typically use a charge-coupled device (ccd) or a contact

image sensor (cis) as the image sensor, whereas older drum scanners use a

photomultiplier tube as the image sensor. A rotary scanner, used for high-

speed document scanning, is another type of drum scanner, using a ccd

array instead of a photomultiplier.

scanners


drum scanners

drum scanners capture image information with photomultiplier

tubes (pmt). Reflective and transmissive originals are mounted on

an acrylic cylinder, the scanner drum, which rotates at high speed

while it passes the object being scanned in front of precision

optics that deliver image information to the pmts. While prices of

both new and used units have come down over the last decade,

they still require a considerable monetary investment when

compared to ccd flatbed and film scanners.

however, drum scanners remain in demand due to their capacity

to produce scans that are superior in resolution, color gradation,

and value structure. Also, because drum scanners are capable of

resolutions up to 12,000 ppi, their use is generally recommended

when a scanned image is going to be enlarged.


flatbed scanners

A flatbed scanner is usually composed of a glass pane (or platen), under

which there is a bright light (often xenon or cold cathode fluorescent)

which illuminates the pane, and a moving optical array in ccd scanning.

ccd-type scanners typically contain three rows (arrays) of sensors with

red, green, and blue filters. Ccd’s quality is determined by the range of

the light density it can register.High end flatbed scanners can read upto

3.8 density.

images to be scanned are placed face down on the glass, an opaque

cover is lowered over it to exclude ambient light, and the sensor array

and light source move across the pane, reading the entire area. An

image is therefore visible to the detector only because of the light it

reflects.


the process of scanning

scanner settings- these can be changed from the scanner control

window. The different modes are used to scan different types of

originals.

+ Flatbed reflective- for opaque images

+ transmissive- for transparent positives

+ Negative- for film negatives

mode there are two modes available namely the rgB mode (wider gamut) and

the cmyk mode (limited gamut).


resolution the resolution for scanning can also be changed. A minimum of 300 dpi at

100% size is considered approprite for both greyscale and colour images.

higher resolutions are used when the scanned image needs to be resiized.

For line drawings and bitmap images the resolution should be a mininmum

of 1200 dpi.

to scan the printed image having halftone,select descreen to avoid image

clash or moiré pattern.it smoothens the image and hence clarity is lost and

the image is blurred.


Jpeg : Joint photographic experts groupIt has various file compression techniques. It is known as lossy format

i.E. While compressing some data is permanently omitted from the file,

resulting in poor quality images.

tiff : tag image File FormatA popular lossless image format supported by majority of image editing

programs.

file formats

giff : graphic interchange File FormatIt is a lossless image file format,pixels are lost

eps : encapsulated postscriptit has a low resolution screen preview.A standard format for drawing, image

or complete page layout, allowing it to be placed into ther documents.


in prepress, imposition means the arrangement of pages on the press sheet

so that when folded the pgaes read consicutively.

the arrangement of the pages on the sheet depends on the size of the

press sheet and the pages and lastly the folding and binding of the job.

imposition


imposition depends on the following factors

the type anD size Of the pressWhether the press is sheet fed or web fed and the size of the press

sheet.

methOD Of binDinG

DesiGnimposition also depends on the design of the printed pieces.

Whether the printing is multicolour, process colour or single colour

and whether both sided are printed.Also whether one or several

duplicate images are to be reproduces on the same side of the sheet.

the type Of paperWhether the image position in relation to grain direction will affect

the folding operation.


printer’s marks

crop marksLines printed in the margins of sheet which indicate to the printer and

bindery where the finished product should be trimmed.Its also used to show

which part of a photo should be used and which should be cropped off.

registration marksthe printed marks that are used to align the colour seperations for printing

so that each colour registers with each other.

bleed marksThe term bleed is used for all objects overlapping the border off your

document. two kinds of bleed a bleed can be a full bleed or partial bleed.

With a full bleed you have objects running of your document on all sides.

With a partial bleed you’ll have a couple of elements running off the

document.if the document has objects with bleed the size of the object

must be bigger than the required printing area.


one side impositionin this type of imposition the printing plate is used to print only one side

of the sheet as it passes through the printing press.

types of impositions

ganged impostionFor verysmall sizes smaller than the smallest size of the paper that can be

fed into the press), multiple copies of the same jobs are imposed oe another

job is imposed on the plate of a bigger size.

gripper edge

side

grip

side

grip

gripper edge

JoB A

JoB B

JoB B

JoB AJoB A


sheetWise imposition

in this one plate is used to print on one side of the press sheet

and a second plate containing different information is then

made, the sheets ar turned over, and the sheets are printed on te

othr side from the second plate.

in the process of printing using sheetwise impositoin, the paper

is turned to enable printing on the other side using two methods:

WOrk anD turnin this the gripper edge remains the same and the side rule

changes and the paper is flipped from left to right.

WOrk anD tumbLe in this the gripper edge change to the other side and the side

rule remains the same and the paper is turned.

gripper edge

side

grip

8 5

1 4

side

grip

gripper edge

6 7

3 2


signature imposition

A large single sheet that is frequently passed through

a printing press and then folded and trimmed to form

a portion of a book or magazine is called signature

imposition.4,8,12,16,24 And 48 page signatures are common.

Work and turn imposition

this type of imposition is used when the paper is printed on both sides uing

a single plate. In this process the paper is flipped from left to right to print on

the other side. hence the gripperedge remains the same.

gripper edge

side

grip

1

cutting

folding

6345

7218

gripper edge

side

grip

1

cutting

folding5436

8127


history of paper

papyruspapyrus is a thick paper like material produced from the pith of papyrus

plants, a wetland sedge that was once abundant in the nile delta in

egypt.It was first manufactured in egypt as far as 3rd millenium bc.

bOnedurint the shang(1600-1050 bc) and zhou(1050bc- 256ad) dynasties of

ancient china documents were written on bone or bamboo tablets ot

bamboo strips were sewn and rolled togetherinto scrolls.

paper


Wood pulp was first used in 105 ad.

the basic process that is follwed in the manufacturing of paper is:

types of paper

cOnstructiOn/ suGar paperit is a coarse coloured paper available in large sheets. its texture is slightly

rough and has an unfinished surface. Most commonly used in grade

school projects.

inkjet paperThis paper is designed for inkjet printers and is identified by its typical

weight,,brightness, opacity and smoothness.


phOtOpaperthis belongs to a category of inkjet paper and is used for reprouction os

photographs.It is available in glossy,semi-matte(silk) or matte finishes.

glossy photo paper

It is the most popular kind of photopaper and has aa shinny finish

matte photo paper

it is less shinny and gives super quality text results.

In offset litho and photographic printing, glossy paper gives highest

colour density (dmax), therefore the widest colour gamut.


printing quality paper

neWsprintit is a low cost, low quality and a non archival paper.sit is made by a

mechanical milling process without using chemical processes to remove

lignin. It is used to print newspapers and flyers.

WOve paperit is most commonly known as writing paper and has a uniform surface.

it is not ribbes or watermarked and is used to print text books.

bOnD paperit is a high quality durable writing paper and contains more rag pulp

which produces paper stronger than wood pulp.its weight is more than

50g/m2 .it also contains a watermark.it is used for government bonds,

letterheads and in electronic printers.


tracinG paperit is a translucent paper which is oil and grease resistant but highly

impervious to water.

map LithOthe top surface of this paper is smooth and is used for books and leaflets.

Offsetthis paper is rough on both sides and has more rag pulp content . it is

considered good for folding.

DupLex bOarDit is box board and is used in cartons.


cartriDGeit is the most expensive paper and has more rag content . it is used for

printing certificates and stamp paper.

chrOmOit is a one side coated paper.

art paperthis paper has a china clay coating on the porous side and has a smooth

finish. It is available in matte and glossy finish.

mirrOr cOatAlso known as cast coat, this paper has a china clay coating in mirror finish

on one side.

carDsthis paper is thick and is sold in gross [144 sheets], but is also avalaible in

packs of 100 sheets.


paper standards and sizes

paper is sold in two standards-

British standard

international (american) standard

internatiOnaL stanDarDs these include three basic series of sizes namely:

+ A series

+ B series

+ c series

All the three series have a proportion of 1:√2 (width : length)

among the individual series and also between the sizes within the series.

the international standard papers are weighed in grams per square

meter (gsm).

A seiers - general printing

B series - posters, large format printing

c series - envelopes for a series

1000 x 1414 mm

917 x 1297 mm

841 x 1189 mm

ab

c


standard subdivision

a0

a1

a2

a3

a4

1

√2

Folio division

a1

a2 a3

a4 a5

a6

a7


british stanDarDin india we still use these standards for paper. the british

standard paper is weighed in kgs.

Fullscap - 13.5” X 17”

denvy - 17.5” X 22.5”

medium - 18” x 23”

royal - 20” x 25”

crown - 15” x 20”

imperial - 22” x 30”

special sizes

DOubLe crOWnWhen the smaller side of the paper is multiplied by 2 you get

a double crown size of the respective size.

crown = 15” x 20”

15” 15”

20”

double crown = 30” x 20”


quaDWhen both sides of the paper is multiplied by 2 you get

4 times the original size known as a quad.

fOLiOWhen paper is divided into half on the longer side it

is called a folio.

15”

20”

15”

20”

quad crown = 30” x 40”

FoLio

4to

8vo

16mo

32mo


the following operations are included in the post press operation:

+ cutting

+ Folding

+ collating

+ gathering

+ Binding

+ packaging

post press operations


cuttinG

the machine typically used for cutting large web-type substrates into

individual pages or sheets is called a guillotine cutter or “paper cutter”.

These machines are built in many sizes, capacities, and configurations. In

general, however, the cutter consists of a flat bed or table that holds the

stack of paper to be cut. At the rear of the cutter the stack of paper rests

against the fence or back guide which is adjustable. the fence allows the

operator to accurately position the paper for the specified cut. The side

guides or walls of the cutter are at exact right angles to the bed. A clamp is

lowered into contact with the top of the paper stack to hold the

stack in place while it is cut. the cutting blade itself is normally powered

by an electric engine operating a hydraulic pump. however, manual lever

cutters are also still in use.


the cutter operator uses a cutting layout to guide the cutting operation.

typically, the layout is one sheet from the printing job that has been

ruled to show the location and order of the cuts to be made. though

cutting is generally considered a postpress operation, most lithographic

and gravure web presses have integrated cutters as well as equipment

to perform related operations such as slicing and perforating.


foldingFolding largely completes postpress operations for certain products such

as simple folded pamphlets. other products are folded into bunches,

known as signatures, of from 16 to 32 pages. multiple signatures are then

assembled and bound into books and magazines.

knife fOLDinGthe knife folding system works by striking the

paper with a knife between two rollers. this knife

is not actually sharp enough to cut through the

paper, it simply strikes the paper along the line

through which the fold is desired. many modern

folders however, have a combination of both knife

and buckle folding mechanisms.


buckLe fOLDinG

Buckle folders work by feeding the paper at high speeds until it hits a

stop. the reaction of the paper is to buckle. high friction rollers will then

grip the paper and pull it through, that is, the paper is folded by being

squeezed between two high friction rollers. the grip of the rollers is

caused by the help of rubber or pu. the front edge of the paper went into

a so called “pocket”. the rollers press on each other by help of a spring.

the distance between the rollers can be set.


there are 2 types of feeding systems used by folders:

The first is flat pile, this is where the paper is placed on a feeding table

and each sheet is then transported into the machine by friction or an air-

controlled suction-wheel.

the second type is called “round pile”; this involves the sheets being

placed onto a belt on a table or rollers, which takes it around the end

of the machine and then each sheet is individually pulled into the

machine by an air-controlled suction-wheel. the sheets of paper will be

separated by help of blowin

cOLLatinGcollating refers to the arranging individual sheets in proper order.

GatherinGit s the assembling of the signatures of a book in proper sequence.


Binding is the fastening of gathered sheets or collated

sheets or signatures.it is the process of physically

assembling a book from a number of folded or ynfolded

sheets of paper.

binding


centre stitch

in saddle binding one or more signatures are fastened along

their folded edge of the unit. the term saddle

Binding comes from an open signature’s resemblance to an

inverted riding saddle. saddle binding is used extensively

for news magazines where wire stitches are placed in the

fold of the signatures. most saddle stitching is performed

automatically in-line during the postpress operations. Large

manually operated staplers are

Used for small printing jobs. Another saddle binding process

called smythe sewing is a center sewing process. it is

considered to be the highest quality fastening method used

today and will produce a book that will lie almost flat.

Wire stitching


saddle stitched books are constructed with sheets that are printed

front and back that represent four pages of a book. the sheets of

four pages are stacked with other sheets in the correct page order

and then stapled along the fold line or saddle.

the stapling is accomplished on equipment that cuts staples from

a continuous roll of wire mounted on the machine and inserts them

into the paper. some machines can do the folding and stitching in

one operation. many booklet manufacturers use this multiple task

equipment to increase efficiency.

saddle stitched binding can work for volumes up to 128 pages (32

sheets, printed with 2 pages front and back) if the paper stock is

thin enough, but it just isn’t practical for anything larger. the larger

the quantity of sheets, the greater the problem with a phenomenon

called page “creep”.


creep refers to the inner sheets sticking out further than those closer to

the outside, because of the paper thickness. to compensate for this, the

pages are “shingled”, which means that the inner margin, or “gutter”,

is increased on the pages working from the inside of the book to the

outside.

Another saddle binding process called smythe sewing is a center sewing

process. it is considered to be the highest quality fastening method

used today and will produce a book that will lie almost flat.


side stitchingin side binding, a fastening device is passed at a right angle through a

pile of paper. stapling is an example of a simple form of side binding.

the three other types of side binding are mechanical, loose-leaf, and

sidesewn binding.

Looseleaf bindings generally allow for the removal and addition of

pages. this type of binding includes the well known three-ring binder.

side-sewn binding involves drilling an odd number of holes in the

binding edge of the unit and then clamping the unit to prevent it

from moving. A needle and thread is then passed through each hole

proceeding from one end of the book to the other and then back

again to the beginning point. this type of stitch is called a buck-stitch.

The thread is tied off to finish the process. Both semiautomatic and

automatic machines are widely used to perform side-stitching. the

main disadvantage of this type of binding is that the book will not lie

flat when opened.


instead of staples being inserted into the side or saddle of the pages,

staples are inserted into the top of the gathered sheets or pages and

pressed down vertically until reaching the back side of the booklet. it is

often used as a means to bind a larger quantity of sheets together than

can be saddle stitched.


office stationary

Adhesive binding, also known as padding, is the simplest

form of binding. it is used for note pads and paperback

books, among other products. in the adhesive binding

process, a pile of paper is clamped securely together in

a press. A liquid glue is then applied with a brush to the

binding edge. the glue most commonly used in binding is

a water-soluble latex that becomes impervious to water

when it dries. For note pads, the glue used is flexible and

will easily release an individual sheet of paper when the

sheet is pulled away from the binding. Adhesive bindings

are also used for paperback books, but these bindings

must be strong enough to prevent pages from pulling out

during normal use.

adhesive binding


For paperback book binding, a hotmelt glue with much greater adhesive

strength than a water-soluble latex is applied. A piece of gauze-like

material is inserted into the glue to provide added strength.

some printed applications are padded into tablets or booklets with the

use of an adhesive applied to one edge of a group of sheets.padding

techniques are actually a form of binding, but the resulting pad or

booklet is not intended to remain permanently bound – the padded edge

serves only to keep the sheets together until a sheet is used and then

detached from the padded edge. most of the padded products begin

as single sheet items, which are then gathered and padded into various

quantities to create note and memo pads, prescription pads, coupon

pads, and many other similar applications. the padding compound is

usually a type of glue, which dries to a soft or semi-hard consistency.

there are various types of glue used, such as varieties applied manually

as a cold application and other varieties applied by machine as a hot

melt application. note: your vendor may have limitations on the number

of sheets that can be padded as well as the minimum and maximum

paper weights that can be manufactured into pads.


perfect binding is often used, and gives a result similar to paperback

books. national geographic is one example of this type. paperback or soft

cover books are also normally bound using perfect binding. they usually

consist of various sections with a cover made from heavier paper, glued

together at the spine with a strong flexible glue. The sections are rough-

cut in the back to make them absorb the hot glue. the other three sides

are then face trimmed. this is what allows the magazine or paperback

book to be opened. mass market paperbacks (pulp paperbacks) are small

(16mo size), cheaply made and often fall apart after much handling or

several years. thermal binding uses a one piece cover with glue down the

spine to quickly and easily bind documents without the need for punching.

the paper is placed in the cover, heated in a machine (basically a griddle),

and when the glue cools, it adheres the paper to the spine. thermal glue

strips can also be purchased separately for individuals that wish to use

customized/original covers.

perfect binding

lose leaf binding


spiral binding is the most economical form of mechanical binding

when using plastic or metal. it is commonly used for atlases and other

publications where it is necessary or desirable to be able to open the

publication back on itself without breaking the spine. there are several

types but basically it is made by punching holes along the entire length

of the spine of the page and winding a wire helix (like a spring) through

the holes to provide a fully flexible hinge at the spine. Spiral coil binding

uses a number of different hole patterns for binding documents. The

most common hole pattern used with this style is 4:1 pitch (4 holes per

inch). however, spiral coil spines are also available for use with 3:1 pitch,

5:1 pitch and 0.400-hole patterns.

spiral binding


comb Binding uses a 9/16" pitch rectangular hole pattern punched

near the bound edge. A curled plastic "comb" is fed through the

slits to hold the sheets together. comb binding allows a book

to be disassembled and reassembled by hand without damage.

comb supplies are typically available in a wide range of colors and

diameters. the supplies themselves can be re-used or recycled.

in the United states, comb binding is often referred to as 19-ring

binding because it uses a total of 19 holes along the 11-inch side of a

sheet of paper.

comb binding


there is only one manufacturer for this type of binding, so

it is a trademarked brand name. security strips are used

for the binding of pages and it is most often used for legal

documents and publications. the equipment used for this

type of binding is expensive. pages cannot be added or

removed unless the security strip is cut.

VeloBind is used to permanently rivet pages together using

a plastic strip on the front and back of the document. sheets

for the document are punched with a line of holes near

the bound edge. A series of pins attached to a plastic strip

called a comb feeds through the holes to the other side and

then goes through another plastic strip called the receiving

strip. The excess portion of the pins is cut off and the plastic

heat-sealed to create a relatively flat bind method. VeloBind

provides a more permanent bind than comb-binding, but is

primarily used for business and legal presentations and small

publications.

velo binding


Library binding is the term used to describe the method of binding

serials, and re-binding paperback or hardcover books, for use within

libraries. Library binding increases the durability of books, as well as

making the materials easier to use. A lower cost and in-house alternative

to library binding of paperbacks is the stiffening process.

library binding

seWn soft cover

occasionally the pages of a book are attached to paperback or soft

covers with the use of strong thread, which is sewn through the

pages and cover using special equipment. this binding method is

often preferred for technical manuals and textbooks, which may be

handled often by a number of people. it is more durable than perfect

binding or wire binding where the overuse of a book may cause the

binding to fail at a faster rate.


self-covers are made from the same material as the body of the printed

product. newspapers are the most common example of a printed

product that uses self-covers. soft covers are made from paper or paper

fiber material that is somewhat heavier or more substantial than the

paper used for the body of the publication.

this type of cover provides only slight protection for the contents.

Unlike self-cover, soft covers almost never contain part of the message

or text of the publication. A typical example of the soft cover is found

on paper-back books. These covers are usually cut flush with the inside

pages and attached to the signatures by glue, though they can also be

sewn in place.


Different types of signatures


hardcover binding

A hardcover, hardbound book has rigid covers and is stitched in the

spine. Looking from the top of the spine, the book can be seen to

consist of a number of signatures bound together. When the book is

opened in the middle of a signature, the binding threads are visible.

signatures of hardcover books are typically octavo (a single sheet

folded three times), though they may also be folio, quarto, or 16mo

(see Book size). Unusually large and heavy books are sometimes

bound with wire. A variation of the hardcover which is more durable

is the calf-binding, where the cover is either half or fully clad in

leather, usually from a calf. this is also called full-bound or, simply,

leather bound. Library inding refers to the hardcover binding of

serials and paperback books intended for the rigors of library use.

though many publishers have started to provide “library binding”

editions, many libraries elect to purchase paperbacks and have them

rebound as hardcover books, resulting in longer life for the material.


casebound covers are the rigid covers generally associated with high-

quality bound books. this method of covering is considerably more

complicated than any of the other methods. signatures are trimmed by

a three-knife trimming machine to produce three different lengths of

signature. This forms a rounded front (open) edge to give the finished

book an attractive appearance and provides a back edge shape that

is compatible with that of the cover. A backing is applied by clamping

the book in place and splaying or mushrooming out the fastened edges

of the signatures. this makes the rounding operation permanent and

produces a ridge for the casebound cover.


gauze and strips of paper are then glued to the back edge in a process

called lining-up. the gauze is known as “crash” and the paper strips are

called “backing paper.” these parts are eventually glued to the case for

improved strength and stability. headbands are applied to the head

and tail of the book for decorative purposes. the case is made of two

pieces of thick board, called binder’s board, that is glued to the covering

cloth or leather. the covering material can be printed either before or

after gluing by hot-stamping or screen methods. The final step in case

binding consists of applying end sheets to attach the case to the body of

the book.


seWn case binding

sewn case binding, also known as “edition binding”, is the most

expensive binding method, but is the most durable. it can be used for any

book thickness, but the most common thicknesses range from 1/4” up to

3”. A number of steps are required to complete a sewn case bound book,

so the process is very automated. A large printed sheet containing 16

or 32 individual book pages, called a signature, is cut apart, folded, and

assembled in the correct page order.


the signature is sewn together with other signatures.endleave papers, which are usually made of heavier

stock than the other pages of the book, are glued to the outside of the first and last signatures. The book

is trimmed on three sides. the sewn edge (spine) of the book is coated with glue. the spine of the book is

rounded in a machine to allow the cover of the book to function properly when it is attached. A strip of gauze

is wrapped around the spine of the book. the cases (covers) that will be used for the book are made from

heavy board stock with its grain running parallel to the spine of the book to prevent warping of the cover.

the heavy board cases are wrapped with embossed paper, cloth, plastic coated material, leather, or other

materials to form the final covering. The book is attached to its hard case/cover on a casing-in machine,

which glues the endleave papers to the case.The final step is to insert the book into a hydraulic press to

ensure that it dries properly and does not warp.


costing and estimations


case study 1:

specificatiOns:name of job-

number of colours-

finished size-

quantity-

a] paper : [name][size][weight]unfinished size-

number of jobs per plate-

quantity

----------------------------- = total number of sheets

number of jobs per plate

total number of sheets

--------------------------- = total number of reams

500

total number of reams x cost per ream = total cost of paper


B] positives :unfinished size = [ ] cm x [ ]cm

size in sq.cm x cost per sq.cm =cost of positive making

C] plate making :number of colours = number of plate

number of plates x cost of one plate = cost of plate making

D] printing :number of plates x number of copies x cost of one colour (per plate, per 100

copies) = printing cost

(includes ink, labour, overheads,etc)

e] Cutting, finishing, folDing :A+B+C+D+E =total cost +10% (printer’s margin) = final cost

final cost

--------------------- = Cost per Copy number of coipes


case study 2 (for books and booklets)

specificatiOns:number of copies of the book-

finished size of the book-

inside paper-[name][size][weight]

cover-[name][size][weight]

inside pages- 1+1 colour (number of pages)

cover- 2+0 colour

a] paper : inside paper- [name][size][weight]finished size= [ ]” x[ ]”

opensize=[ ]” x[ ]”

number of pages per sheet=

total number of pages

-------------------------------- = number of sheets per book

number of pages per sheet


number of sheets x number of copies= number of sheets for all books

number of sheets for all books + 10% (pre press) = total number of sheets


--------------------------- = number of reams

500

number of reams x cost per ream = total cost of inside paper

B] paper : cover paper-[name][size][weight]

number of copies = [ ]+ 10% (pre press)

number of copies

--------------------------------- = total number of sheets

number of covers per sheet


--------------------------------- = total number of packets

number of sheets per packet


number of packets x cost per packet = total cost of cover paper

C] layout anD plate making :

total number of sheets x 2 (for front and back) = number of plates

number of plates (inside paper) x cost per plate = cost of plates for inside pages --------- [1]

number of plates (cover pages) x cost per plate = cost of plates for cover pages --------- [2]

[1] + [2] = total cost of plate making

D] proCessing: image setting (positives)

total number of pages

---------------------------- = number of positives

2

number of positives x cost per positive = cost of positives of inner pages ------------[3]

(inner pages)


number of positives x cost per positive = cost of positives of cover pages ------------[4]

(cover pages)

[3] + [4] = total cost of positives

e] printing :

number of plates printed x number of copies x cost per colour(plate) = cost of printing ---------[5]

(inner pags) (inner pages)

number of plates printed x number of copies x cost per colour(plate) = cost of printing ---------[6]

(cover pags) (cover pages)

[5] + [6] = total cost of printing


A + B + c + d + e + F = total cost +10% (printers margin)

total cost

--------------------- = Cost per Booknumber of copies

f] post press opereations :

number of copies x cost per copy = total cost of post press operations


field visits and practicals


on our feild visit to the art-o-print press we got the

opportunity to see how printing jobs are done at a

large scale and how it is done for mass production.

We also got to see the ctp machine. it was fascinating

to watch all the processes happen under one roof and

also how fast they happen. it gave us an experience of

actual industrial printing.

field visit


on our visit to a factory where corrugated boxes were

made we saw how corrugation is done at a large scale

and how die cutting happens. Under one roof, we saw

how paper was cut, corrugated, pasted to form 2 ply

upto 7ply sheets then die cut and folded and finally

wire stitched to form cartons.

field visit


During the practical in offset printing we made artworks that were

then imposed on the plate and exposed pre sensitised plates by

using film negatives of hte artwork with UV light. The plate was

then clamped on the plate cyinder and prints were taken to set

the amount of ink. We saw the progressive prints to obtain the

right amount of ink and proper registration of different colours.

practicals


in the practical for screen printing we saw how the screen is

made using a light sensitive film by exposing to uv light and

then developed by washing . the solution in the printing areas

is washed offf and the holes arec leared off the solution where

as the solution in the non printing areas hardens and bolcks the

holes. the screen is then clamped and ink is transfered to the

paper by using the squeeze. We explored by printing on a variety

of surfaces.

For binding we were exposed to the different binding methods

and their relevance to the kind of publications. We did each

method by ourselves which gave us indepth understanding in

how every method is executed.


class notes

wkipedia

www.google com

www.printingtips.com

www.science.jrank.org

international paper knowledge centre

special thanks to -

Bharat suthar & tridha gajjar

bibliography

the book of printing technology

Documents

platen printing

printing area

matrix printing plate

ancient method of printing

printing smalltown newspapers

technologythe platen

inked plate

inking plate