CHAPTER – 3

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CHAPTER-3

Techniques

3.3.1 Lithography

Lithography (from Greek λίθος - lithos, 'stone' + γράφω - graphο,

'to write') is a method for printing using a stone (lithographic limestone)

or a metal plate with a completely smooth surface. Invented in 1796 by

Bavarian author Alois Senefelder as a low-cost method of publishing

theatrical works, lithography can be used to print text or artwork onto

paper or another suitable material.

Lithography originally used oil or fat. However, in modern times,

the image is now made of polymer applied to anodized aluminium plates.

The smooth surface is divided into hydrophilic regions that accept a film

of water and while damp these areas reject ink, and hydrophobic (water

repelling) regions which accept ink because the surface tension is higher

on the greasier image area which remains dry because the water will part

and run off the greasy image. This process is quite different to gravure or

intaglio printing where a plate is engraved, etched or stippled to make

cavities to contain the printing ink, and in woodblock printing and

letterpress ink (non waterproof) is applied to the raised surfaces of letters

or images.

Most books, indeed all types of high-volume text, are now printed

using offset lithography, the most common form of printing production.

The word "lithography" also refers to photolithography, a

microfabrication technique used to make integrated circuits and

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microelectromechanical systems, although those techniques have more in

common with etching than with lithography.

Lithography: a modus utilized in offset printing. Offset printing

principally covers the idea that the printing plate, printing and non

printing surfaces exist. Contact between ink, water and the printing plate

is the norm. Initially, use of oil and fat was common.

The Principle of Lithography

Lithography uses simple chemical processes to create an image.

For instance, the positive part of an image would be a hydrophobic, or

"water hating" chemical, while the negative image would be hydrophilic

or "water loving". Thus, when the plate is introduced to a compatible

printing ink and water mixture, the ink will adhere to the positive image

and the water will clean the negative image. This allows a flat print plate

to be used, enabling much longer and more detailed print runs than the

older physical methods of printing (e.g., intaglio printing, Letterpress

printing.

Lithography was invented by Alois Senefelder in Bohemia in 1796.

In the early days of lithography, a smooth piece of limestone was used

(hence the name "lithography"—"lithos" (λιθος) is the ancient Greek

word for stone). After the oil-based image was put on the surface, a

solution of gum arabic in water was applied, the gum sticking only to the

non-oily surface. During printing, water adhered to the gum arabic

surfaces and avoided the oily parts, while the oily ink used for printing

did the opposite.

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Lithography on Limestone

Lithography stone and mirror-image print of a map of Munich.

Figure (XI)

Lithography works because of the mutual repulsion of oil and

water. The image is drawn on the surface of the print plate with a fat or

oil-based medium (hydrophobic), which may be pigmented to make the

drawing visible. A wide range of oil-based media is available, but the

durability of the image on the stone depends on the lipid content of the

material being used, and its ability to withstand water and acid. Following

the drawing of the image, an aqueous solution of gum arabic, weakly

acidified with nitric acid HNO3 is applied to the stone. The function of

this solution is to create a hydrophilic layer of calcium nitrate salt,

Ca(NO3)2, and gum arabic on all non-image surfaces. The gum solution

penetrates into the pores of the stone, completely surrounding the original

image with a hydrophilic layer that will not accept the printing ink. Using

lithographic turpentine, the printer then removes any excess of the greasy

drawing material, but a hydrophobic molecular film of it remains tightly

bonded to the surface of the stone, rejecting the gum arabic and water, but

ready to accept the oily ink[27].

When printing, the stone is kept wet with water. Naturally the

water is attracted to the layer of gum and salt created by the acid wash.

Printing ink based on drying oils such as linseed oil and varnish loaded

with pigment is then rolled over the surface. The water repels the greasy

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ink but the hydrophobic areas left by the original drawing material accept

it. When the hydrophobic image is loaded with ink, the stone and paper

are run through a press which applies even pressure over the surface,

transferring the ink to the paper and off the stone.

Senefelder had experimented in the early 1800s with multicolour

lithography; in his 1819 book, he predicted that the process would

eventually be perfected and used to reproduce paintings. Multi-colour

printing was introduced through a new process developed by Godefroy

Engelmann (France) in 1837 known as Chromolithography. [28]. A

separate stone was used for each colour, and a print went through the

press separately for each stone. The main challenge was of course to keep

the images aligned (in register). This method lent itself to images

consisting of large areas of flat colour, and led to the characteristic poster

designs of this period.

The Modern Lithographic Process

A 1902 lithograph map

Figure (XII)

The earliest regular use of lithography for text was in countries

using Arabic, Turkish and similar scripts, where books, especially the

Qu'ran, were sometimes printed by lithography in the nineteenth century,

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as the links between the characters require compromises when movable

type is used which were considered inappropriate for sacred texts.

High-volume lithography is used today to produce posters, maps,

books, newspapers, and packaging — just about any smooth, mass-

produced item with print and graphics on it. Most books, indeed all types

of high-volume text, are now printed using offset lithography.

In offset lithography, which depends on photographic processes,

flexible aluminum, polyester, mylar or paper printing plates are used in

place of stone tablets. Modern printing plates have a brushed or

roughened texture and are covered with a photosensitive emulsion. A

photographic negative of the desired image is placed in contact with the

emulsion and the plate is exposed to ultraviolet light. After development,

the emulsion shows a reverse of the negative image, which is thus a

duplicate of the original (positive) image. The image on the plate

emulsion can also be created through direct laser imaging in a CTP

(Computer-To-Plate) device called a platesetter. The positive image is the

emulsion that remains after imaging. For many years, chemicals have

been used to remove the non-image emulsion, but now plates are

available that do not require chemical processing.

Lithography press for printing maps

Figure (XIII)

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The plate is affixed to a cylinder on a printing press. Dampening

rollers apply water, which covers the blank portions of the plate but is

repelled by the emulsion of the image area. Ink, which is hydrophobic, is

then applied by the inking rollers, which is repelled by the water and only

adheres to the emulsion of the image area—such as the type and

photographs on a newspaper page.

If this image were directly transferred to paper, it would create a

mirror image and the paper would become too wet. Instead, the plate rolls

against a cylinder covered with a rubber blanket, which squeezes away

the water, picks up the ink and transfers it to the paper with uniform

pressure. The paper rolls across the blanket drum and the image is

transferred to the paper. Because the image is first transferred, or offset to

the rubber drum, this reproduction method is known as offset lithography

or offset printing. [29].

Many innovations and technical refinements have been made in

printing processes and presses over the years, including the development

of presses with multiple units (each containing one printing plate) that

can print multi-colour images in one pass on both sides of the sheet, and

presses that accommodate continuous rolls (webs) of paper, known as

web presses. Another innovation was the continuous dampening system

first introduced by Dahlgren instead of the old method which is still used

today on older presses (conventional dampening), which are rollers

covered in molleton (cloth) which absorbs the water. This increased

control over the water flow to the plate and allowed for better ink and

water balance. Current dampening systems include a "delta effect or

vario" which slows the roller in contact with the plate, thus creating a

sweeping movement over the ink image to clean impurities known as

"hickies".

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The advent of desktop publishing made it possible for type and

images to be manipulated easily on personal computers for eventual

printing on desktop or commercial presses. The development of digital

imagesetters enabled print shops to produce negatives for platemaking

directly from digital input, skipping the intermediate step of

photographing an actual page layout. The development of the digital

platesetter in the late twentieth century eliminated film negatives

altogether by exposing printing plates directly from digital input, a

process known as computer to plate printing.

Photolithography

'City of Words', lithograph by Vito Acconci, 1999

Figure (XIV)

Microlithography and nanolithography refer specifically to

lithographic patterning methods capable of structuring material on a fine

scale. Typically features smaller than 10 micrometers are considered

microlithographic, and features smaller than 100 nanometers are

considered nanolithographic. Photolithography is one of these methods,

often applied to semiconductor manufacturing of microchips.

Photolithography is also commonly used in fabricating MEMS devices.

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Photolithography generally uses a pre-fabricated photomask or reticle as

a master from which the final pattern is derived.

Although photolithographic technology is the most commercially

advanced form of nanolithography, other techniques are also used. Some,

for example electron beam lithography, are capable of much higher

patterning resolution (sometime as small as a few nanometers). Electron

beam lithography is also commercially important, primarily for its use in

the manufacture of photomasks. Electron beam lithography as it is

usually practiced is a form of maskless lithography, in that no mask is

required to generate the final pattern. Instead, the final pattern is created

directly from a digital representation on a computer, by controlling an

electron beam as it scans across a resist-coated substrate. Electron beam

lithography has the disadvantage of being much slower than

photolithography.

3.3.2 Etching

The Soldier and his Wife. Etching by Daniel Hopfer, who is believed to have been the first to

apply the technique to printmaking

Figure (XV)

Etching is the process of using strong acid or mordant to cut into

the unprotected parts of a metal surface to create a design in intaglio in

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the metal (the original process—in modern manufacturing other

chemicals may be used on other types of material). As an intaglio method

of printmaking it is, along with engraving, the most important technique

for old master prints, and remains widely used today.

Basic Method

Rembrandt, The Virgin and Child with a Cat, 1654. Original copper etching plate above,

example of the print below, with composition reversed.

Figure (XVI)

In pure etching, a metal (usually copper, zinc or steel) plate is

covered with a waxy ground which is resistant to acid. [30]. The artist then

scratches off the ground with a pointed etching needle[31]. where he wants

a line to appear in the finished piece, so exposing the bare metal. The

échoppe, a tool with a slanted oval section is also used for "swelling"

lines[32]. The plate is then dipped in a bath of acid, technically called the

mordant (French for "biting") or etchant, or has acid washed over it. The

acid "bites" into the metal, where it is exposed, leaving behind lines sunk

into the plate. The remaining ground is then cleaned off the plate. The

plate is inked all over, and then the ink wiped off the surface, leaving

only the ink in the etched lines.

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The plate is then put through a high-pressure printing press

together with a sheet of paper (often moistened to soften it) [30]. The paper

picks up the ink from the etched lines, making a print. The process can be

repeated many times; typically several hundred impressions (copies)

could be printed before the plate shows much sign of wear. The work on

the plate can also be added to by repeating the whole process; this creates

an etching which exists in more than one state.

Etching has often been combined with other intaglio techniques

such as engraving (e.g. Rembrandt) or aquatint (e.g. Goya).

Christ Preaching, known as The Hundred Guilder print; etching c1648 by Rembrandt.

Figure (XVII)

Origin

Etching by goldsmiths and other metal-workers in order to decorate

metal items such as guns, armour, cups and plates has been known in

Europe since the Middle Ages at least, and may go back to antiquity. The

elaborate decoration of armour, in Germany anyway, was an art probably

imported from Italy around the end of the 15th century—little earlier than

the birth of etching as a printmaking technique. The process as applied to

printmaking is believed to have been invented by Daniel Hopfer (circa

1470–1536) of Augsburg, Germany. Hopfer was a craftsman who

decorated armour in this way, and applied the method to printmaking,

using iron plates (many of which still exist). Apart from his prints, there

are two proven examples of his work on armour: a shield from 1536 now

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in the Real Armeria of Madrid and a sword in the Germanisches

Nationalmuseum of Nuremberg. An Augsburg horse armour in the

German Historical Museum, Berlin, dating to between 1512 and 1515, is

decorated with motifs from Hopfer's etchings and woodcuts, but this is no

evidence that Hopfer himself worked on it, as his decorative prints were

largely produced as patterns for other craftsmen in various media. The

switch to copper plates was probably made in Italy, and thereafter etching

soon came to challenge engraving as the most popular medium for artists

in printmaking. Its great advantage was that, unlike engraving which

requires special skill in metalworking, etching is relatively easy to learn

for an artist trained in drawing.

Callot's Innovations

Jacques Callot (1592–1635) from Nancy in Lorraine (now part of

France) made important technical advances in etching technique. He

developed the échoppe, a type of etching-needle with a slanting oval

section at the end, which enabled etchers to create a swelling line, as

engravers were able to do.

Etching by Jacques Bellange, Gardener with basket c1612

Figure (XVIII)

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He also seems to have been responsible for an improved, harder,

recipe for the etching ground, using lute-makers' varnish rather than a

wax-based formula. This enabled lines to be more deeply bitten,

prolonging the life of the plate in printing, and also greatly reducing the

risk of "foul-biting", where acid gets through the ground to the plate

where it is not intended to, producing spots or blotches on the image.

Previously the risk of foul-biting had always been at the back of an

etcher's mind, preventing him from investing too much time on a single

plate that risked being ruined in the biting process. Now etchers could do

the highly detailed work that was previously the monopoly of engravers,

and Callot made full use of the new possibilities.

He also made more extensive and sophisticated use of multiple

"stoppings-out" than previous etchers had done. This is the technique of

letting the acid bite lightly over the whole plate, then stopping-out those

parts of the work which the artist wishes to keep light in tone by covering

them with ground before bathing the plate in acid again. He achieved

unprecedented subtlety in effects of distance and light and shade by

careful control of this process. Most of his prints were relatively small—

up to about six inches or 15 cm on their longest dimension, but packed

with detail.

One of his followers, the Parisian Abraham Bosse, spread Callot's

innovations all over Europe with the first published manual of etching,

which was translated into Italian, Dutch, German and English.

The 17th century was the great age of etching, with Rembrandt,

Giovanni Benedetto Castiglione and many other masters. In the 18th

Piranesi, Tiepolo and Daniel Chodowiecki were the best of a smaller

number of fine etchers. In the 19th and early-20th century the Etching

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revival produced a host of lesser artists, but no really major figures.

Etching is still widely practiced today.

Variants

Relief etching by William Blake, frontispiece to America a Prophecy (Copy A, printed 1795)

Figure (XIX)

• Aquatint uses acid-resistant resin to achieve tonal effects.

• Soft-ground etching uses a special softer ground. The artist places a

piece of paper (or cloth etc in modern uses) over the ground and

draws on it. The print resembles a drawing.

• Relief etching. Invented by William Blake in about 1788; from

1880–1950 a photo-mechanical ("line-block") variant was the

dominant form of commercial printing for images. A similar

process to etching, but printed as a relief print, so it is the "white"

background areas which are exposed to the acid, and the areas to

print "black" which are covered with ground. Blake's exact

technique remains controversial. He used the technique to print

texts and images together.

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Modern Technique in Detail

A waxy acid-resist, known as a ground, is applied to a metal plate,

most often copper or zinc but steel plate is another medium with different

qualities. There are two common types of ground: hard ground and soft

ground. Hard ground can be applied in two ways. Solid hard ground

comes in a hard waxy block. To apply hard ground of this variety, the

plate to be etched is placed upon a hot-plate (set at 70 degrees C), a kind

of metal worktop that is heated up. The plate heats up and the ground is

applied by hand, melting onto the plate as it is applied. The ground is

spread over the plate as evenly as possible using a roller. Once applied

the etching plate is removed from the hot-plate and allowed to cool which

hardens the ground. After the ground has hardened the artist "smokes" the

plate, classically with 3 beeswax tapers, applying the flame to the plate to

darken the ground and make it easier to see what parts of the plate are

exposed. Smoking not only darkens the plate but adds a small amount of

wax. Afterwards the artist uses a sharp tool to scratch into the ground,

exposing the metal.

Landscape under Trees, etching by Paula Modersohn-Becker 1876–1907

Figure (XX)

The second way to apply hard ground is by liquid hard ground.

This comes in a can and is applied with a brush upon the plate to be

etched. Exposed to air the hard ground will harden. Some printmakers use

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bitumen as hard ground, although often bitumen is used to protect steel

plates from rust and copper plates from aging.

Soft ground also comes in liquid form and is allowed to dry but it

does not dry hard like hard ground and is impressionable. After the soft

ground has dried the printmaker may apply materials such as leaves,

objects, hand prints and so on which will penetrate the soft ground and

expose the plate underneath.

The ground can also be applied in a fine mist, using powdered

rosin or spraypaint. This process is called aquatint, and allows for the

creation of tones, shadows, and solid areas of colour.

The design is then drawn (in reverse) with an etching-needle or

échoppe. An "echoppe" point can be made from an ordinary tempered

steel etching needle, by grinding the point back on a carborundum stone,

at a 45–60 degree angle. The "echoppe" works on the same principle that

makes a fountain pen's line more attractive than a ballpoint's: The slight

swelling variation caused by the natural movement of the hand "warms

up" the line, and although hardly noticeable in any individual line, has a

very attractive overall effect on the finished plate. It can be drawn with in

the same way as an ordinary needle

The plate is then completely submerged in an acid that eats away at

the exposed metal. Ferric chloride may be used for etching copper or zinc

plates, whereas nitric acid may be used for etching zinc or steel plates.

Typical solutions are 2 parts FeCl3 to 2 parts water and 1 part nitric to 3

parts water. The strength of the acid determines the speed of the etching

process.

• The etching process is known as biting (see also spit-biting below).

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• The waxy resist prevents the acid from biting the parts of the plate

which have been covered.

• The longer the plate remains in the acid the deeper the "bites"

become.

Example of etching

Figure (XXI)

During the etching process the printmaker uses a bird feather or

similar item to wave away bubbles and detritus produced by the

dissolving process, from the surface of the plate, or the plate may be

periodically lifted from the acid bath. If a bubble is allowed to remain on

the plate then it will stop the acid biting into the plate where the bubble

touches it. Zinc produces more bubbles much more rapidly than copper

and steel and some artists use this to produce interesting round bubble-

like circles within their prints for a Milky Way effect.

The detritus is powdery dissolved metal that fills the etched

grooves and can also block the acid from biting evenly into the exposed

plate surfaces. Another way to remove detritus from a plate is to place the

plate to be etched face down within the acid upon plasticine balls or

marbles, although the drawback of this technique is the exposure to

bubbles and the inability to remove them readily.

For aquatinting a printmaker will often use a test strip of metal

about a centimetre to three centimetres wide. The strip will be dipped into

the acid for a specific number of minutes or seconds. The metal strip will

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then be removed and the acid washed off with water. Part of the strip will

be covered in ground and then the strip is redipped into the acid and the

process repeated. The ground will then be removed from the strip and the

strip inked up and printed. This will show the printmaker the different

degrees or depths of the etch, and therefore the strength of the ink colour,

based upon how long the plate is left in the acid.

The plate is removed from the acid and washed over with water to

remove the acid. The ground is removed with a solvent such as

turpentine. Turpentine is often removed from the plate using methylated

spirits since turpentine is greasy and can affect the application of ink and

the printing of the plate.

Spit-biting is a process whereby the printmaker will apply acid to a

plate with a brush in certain areas of the plate. The plate may be

aquatinted for this purpose or exposed directly to the acid. The process is

known as "spit"-biting due to the use of saliva once used as a medium to

dilute the acid, although gum arabic or water are now commonly used.

Pornocrates by Félicien Rops. Etching and aquatint

Figure (XXII)

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A piece of matte board, a plastic "card", or a wad of cloth is often

used to push the ink into the incised lines. The surface is wiped clean

with a piece of stiff fabric known as tarlatan and then either wiped with

newsprint paper; some printmakers prefer to use the blade part of their

hand or palm at the base of their thumb. The wiping leaves ink in the

incisions. You may also use a folded piece of organza silk to do the final

wipe. If copper or zinc plates are used plate surface is left very clean and

therefore white in the print. If steel plate is used then the plate's natural

tooth gives the print a grey background similar to the effects of

aquatinting. As a result steel plates do not need aquatinting as gradual

exposure of the plate via successive dips into acid will produce the same

result.

A damp piece of paper is placed over the plate and it is run through

the press.

Non-toxic Etching

Growing concerns about the health effects of acids and solvents[31].

led to the development of less toxic etching methods in the late 20th

century. An early innovation was the use of floor wax as a hard ground

for coating the plate. Others, such as printmakers Mark Zaffron and Keith

Howard, developed systems using acrylic polymers as a ground and ferric

chloride for etching. The polymers are removed with sodium carbonate

(washing soda) solution, rather than solvents. When used for etching,

ferric chloride does not produce a corrosive gas, as acids do, thus

eliminating another danger of traditional etching.

The traditional aquatint, which uses either powdered rosin or

enamel spray paint, is replaced with an airbrush application of the acrylic

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polymer hard ground. Again, no solvents are needed beyond the soda ash

solution, though a ventilation hood is needed due to acrylic particulates

from the air brush spray.

The traditional soft ground, requiring solvents for removal from the

plate, is replaced with water-based relief printing ink. The ink receives

impressions like traditional soft ground, resists the ferric chloride etchant,

yet can be cleaned up with warm water and either soda ash solution or

ammonia. Etching is a form of art which is taught in many ways.

Anodic etching has been used in industrial processes for over a

century. The etching power is a source of direct current. The item to be

etched (anode) is connected to its positive pole. A receiver plate (cathode)

is connected to its negative pole. Both, spaced slightly apart, are

immersed in a suitable aqueous solution of a suitable electrolyte. The

current pushes the metal out from the anode into solution and deposits it

as metal on the cathode. Shortly before 1990, two groups working

independently[32]. developed different ways of applying it to creating

intaglio printing plates.

In the patented Electroetch system, invented by Marion and Omri

Behr, in contrast to certain non toxic etching methods, an etched plate can

be reworked as often as the artist desires[33]. The system uses voltages

below 2 volts which exposes the uneven metal crystals in the etched areas

resulting in superior ink retention and printed image appearance of

quality equivalent to traditional acid methods. With polarity reversed the

low voltage provides a simpler method of making mezzotint plates as

well as the “steel facing” copper plates.

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Photo-Etching

Monserrate Palace, etching by Nathaniel Nguyen 1975–present

Figure (XXIII)

Light sensitive polymer plates allow for photorealistic etchings. A

photo-sensitive coating is applied to the plate by either the plate supplier

or the artist. Light is projected onto the plate as a negative image to

expose it. Photopolymer plates are either washed in hot water or under

other chemicals according to the plate manufacturers' instructions. Areas

of the photo-etch image may be stopped-out before etching to exclude

them from the final image on the plate, or removed or lightened by

scraping and burnishing once the plate has been etched. Once the photo-

etching process is complete, the plate can be worked further as a normal

intaglio plate, using drypoint, further etching, engraving, etc. The final

result is an intaglio plate which is printed like any other.

Types of Metal Plates

Copper was always the traditional metal, and is still preferred, for

etching, as it bites evenly, holds texture well, and does not distort the

colour of the ink when wiped. Zinc is cheaper than copper, so preferable

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for beginners, but it does not bite as cleanly as copper, and it alters some

colours of ink. Steel is growing in popularity as an etching substrate.

Prices of copper and zinc have steered steel to an acceptable alternative.

Line quality of steel is less fine than copper but finer than zinc. Steel has

a natural and rich aquatint. Steel is virtually impossible to reclaim though

the price and availability make it still more cost effective.

Industrial Etching

Etching is also used in the manufacturing of printed circuit boards

and semiconductor devices (see Etching (microfabrication) ), on glass,

and in the preparation of metallic specimens for microscopic observation.

Controlling the Acid's effects

Hard grounds

Young Girl in cafe with street-view, etching by Lesser Ury 1861–1931

Figure (XXIV)

There are many ways for the printmaker to control the acid's

effects. Most typically, the surface of the plate is covered in a hard, waxy

'ground' that resists acid. The printmaker then scratches through the

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ground with a sharp point, exposing lines of metal that are attacked by the

acid.

Aquatint

Aquatint is a variation in which particulate resin is evenly

distributed on the plate, then heated to form a screen ground of uniform

but less than perfect density. After etching, any exposed surface will

result in a roughened (i.e. darkened) surface. Areas that are to be light in

the final print are protected by varnishing between acid baths. Successive

turns of varnishing and placing the plate in acid create areas of tone

difficult or impossible to achieve by drawing through a wax ground.

Example of Sugar Lift and Spit Bite effect

Figure (XXV)

Sugar Lift

Here designs in a syrupy solution of sugar or Camp Coffee are

painted onto the metal surface prior to it being coated in a liquid etching

ground or 'stop out' varnish. When later the plate is placed in hot water

the sugar dissolves and lifts off leaving the image. The plate can then be

etched.

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Spit Bite

A mixture of neat acid and Gum Arabic (or almost never - saliva)

which can be dripped, spattered or painted onto a metal surface giving

interesting results.

Carbograph

This is an etching technique invented in 2006 by the U.S.

printmaker Rand Huebsch. Tiny particles of carborundum grit are mixed

into the acid-resistant ground, which is brushed onto the bare metal as

usual and allowed to dry. When that mixture has dried, the metal stylus is

used on the plate and thereby removes some of the grit particles, so that

minuscule areas of copper are exposed to the acid and etched; they will

eventually hold the ink for the printing process. Thus the image on paper

has a texture similar to that of a charcoal drawing.

Printing

Printing the plate is done by covering the surface with ink, then

rubbing the ink off the surface with tarlatan cloth or newsprint, leaving

ink in the roughened areas and lines. Damp paper is placed on the plate,

and both are run through a printing press; the pressure forces the paper

into contact with the ink, transferring the image (c.f., chine-collé).

Unfortunately, the pressure also subtly degrades the image in the plate,

smoothing the roughened areas and closing the lines; a copper plate is

good for, at most, a few hundred printings of a strongly etched imaged

before the degradation is considered too great by the artist. At that point,

the artist can manually restore the plate by re-etching it, essentially

putting ground back on and retracing their lines; alternately, plates can be

electro-plated before printing with a harder metal to preserve the surface.

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Zinc is also used, because as a softer metal, etching times are shorter;

however, that softness also leads to faster degradation of the image in the

press.

Faults

Faux-bite or "over-biting" is common in etching, and is the effect

of minuscule amounts of acid leaking through the ground to create minor

pitting and burning on the surface. This incidental roughening may be

removed by smoothing and polishing the surface, but artists often leave

faux-bite, or deliberately court it by handling the plate roughly, because it

is viewed as a desirable mark of the process.

Example of Foul Bite in Acid Etching

Figure (XXVI)

3.3.3 Web Design

Web Design is the skill of creating presentations of content

(usually hypertext or hypermedia) that is delivered to an end-user through

the World Wide Web, by way of a Web browser or other Web-enabled

software like Internet television clients, microblogging clients and RSS

readers.

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The intent of web design[1] is to create a web site—a collection of

electronic files that reside on a web server/servers and present content

and interactive features/interfaces to the end user in form of Web pages

once requested. Such elements as text, bit-mapped images (GIFs, JPEGs)

and forms can be placed on the page using HTML/XHTML/XML tags.

Displaying more complex media (vector graphics, animations, videos,

sounds) requires plug-ins such as Adobe Flash, QuickTime, Java run-time

environment, etc. Plug-ins are also embedded into web page by using

HTML/XHTML tags.

Improvements in browsers' compliance with W3C standards

prompted a widespread acceptance and usage of XHTML/XML in

conjunction with Cascading Style Sheets (CSS) to position and

manipulate web page elements and objects. Latest standards and

proposals aim at leading to browsers' ability to deliver a wide variety of

media and accessibility options to the client possibly without employing

plug-ins.

Typically web pages are classified as static or dynamic:

• Static pages don’t change content and layout with every request

unless a human (web master/programmer) manually updates the

page. A simple HTML page is an example of static content.

• Dynamic pages adapt their content and/or appearance depending

on end-user’s input/interaction or changes in the computing

environment (user, time, database modifications, etc.) Content can

be changed on the client side (end-user's computer) by using client-

side scripting languages (JavaScript, JScript, Actionscript, etc.) to

alter DOM elements (DHTML). Dynamic content is often

compiled on the server utilizing server-side scripting languages

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(Perl, PHP, ASP, JSP, ColdFusion, etc.). Both approaches are

usually used in complex applications.

With growing specialization in the information technology field

there is a strong tendency to draw a clear line between web design and

web development.

Web design is a kind of graphic design intended for development

and styling of objects of the Internet's information environment to

provide them with high-end consumer features and aesthetic qualities.

The offered definition separates web design from web programming,

emphasizing the functional features of a web site, as well as positioning

web design as a kind of graphic design.

The process of designing web pages, web sites, web applications or

multimedia for the Web may utilize multiple disciplines, such as

animation, authoring, communication design, corporate identity, graphic

design, human-computer interaction, information architecture, interaction

design, marketing, photography, search engine optimization and

typography.

• Markup languages (such as HTML, XHTML and XML)

• Style sheet languages (such as CSS and XSL)

• Client-side scripting (such as JavaScript)

• Server-side scripting (such as PHP and ASP)

• Database technologies (such as MySQL and PostgreSQL)

• Multimedia technologies (such as Flash and Silverlight)

Web pages and web sites can be static pages, or can be

programmed to be dynamic pages that automatically adapt content or

visual appearance depending on a variety of factors, such as input from

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the end-user, input from the Webmaster or changes in the computing

environment (such as the site's associated database having been

modified).

With growing specialization within communication design and

information technology fields, there is a strong tendency to draw a clear

line between web design specifically for web pages and web development

for the overall logistics of all web-based services.

3.3.4 Publishing and Printing

Printing is a process for reproducing text and image, typically with

ink on paper using a printing press. It is often carried out as a large-scale

industrial process, and is an essential part of publishing and transaction

printing.

History of Printing

The intricate frontispiece of the Diamond Sutra from Tang Dynasty China, AD 868 (British

Museum)

Figure (XXVII)

Woodblock Printing

Woodblock printing is a technique for printing text, images or

patterns that was used widely throughout East Asia. It originated in China

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in antiquity as a method of printing on textiles and later on paper. As a

method of printing on cloth, the earliest surviving examples from China

date to before 220, and from Roman Egypt to the 4th century.

In East Asia

"Selected Teachings of Buddhist Sages and Son Masters", the earliest known book printed

with movable metal type, 1377. Bibliothèque Nationale de Paris.

Fig (XXVIII)

History of Typography in East Asia

By AD 593, woodblock printing was in wide use in China, and the

first printed periodical, the Kaiyuan Za Bao was made available in

Beijing in AD 713. The Tianemmen scrolls, the earliest known complete

example of a woodblock printed book with illustrations, was printed in

China in AD 868.

In Middle East

Woodblock printing on cloth appeared in Roman Egypt by the 4th

century. Block printing, called tarsh in Arabic was developed in Arabic

Egypt during the 9th-10th centuries, mostly for prayers and amulets.

There is some evidence to suggest that the print blocks were made from a

variety of different materials besides wood, including metals such as tin,

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lead and cast iron, as well as stone, glass and clay. However, the

techniques employed are uncertain and they appear to have had very little

influence outside of the Muslim world. Though Europe adopted

woodblock printing from the Muslim world, initially for fabric, the

technique of metal block printing remained unknown in Europe. Block

printing later went out of use in Islamic Central Asia after movable type

printing was introduced from China.

In Europe

Block printing first came to Christian Europe as a method for

printing on cloth, where it was common by 1300. Images printed on cloth

for religious purposes could be quite large and elaborate, and when paper

became relatively easily available, around 1400, the medium transferred

very quickly to small woodcut religious images and playing cards printed

on paper. These prints were produced in very large numbers from about

1425 onwards.

Around the mid-century, block-books, woodcut books with both text

and images, usually carved in the same block, emerged as a cheaper

alternative to manuscripts and books printed with movable type. These were

all short heavily illustrated works, the bestsellers of the day, repeated in

many different block-book versions: the Ars moriendi and the Biblia

pauperum were the most common. There is still some controversy among

scholars as to whether their introduction preceded or, the majority view,

followed the introduction of movable type, with the range of estimated dates

being between about 1440 and 1460.

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Movable Type Printing

A case of cast metal type pieces and typeset matter in a composing stick.

Figure (XXIX)

Movable Type

Movable type is the system of printing and typography using

movable pieces of metal type, made by casting from matrices struck by

letterpunches. Movable type allowed for much more flexible processes

than hand copying or block printing.

Around 1040, the first known movable type system was created in

China by Bi Sheng out of porcelain. Sheng used clay type, which broke

easily, but Wang Zhen later carved a more durable type from wood by

1298 AD, and developed a complex system of revolving tables and

number-association with written Chinese characters that made typesetting

and printing more efficient. However, the main method in use there

remained woodblock printing.

Around 1450, Johannes Gutenberg introduced what is regarded as

an independent invention of movable type in Europe (see printing press),

along with innovations in casting the type based on a matrix and hand

mould. Gutenberg was the first to create his type pieces from an alloy of

lead, tin and antimony – the same components still used today.

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Johannes Gutenberg's work on the printing press began in

approximately 1436 when he partnered with Andreas Dritzehen — a man

he had previously instructed in gem-cutting—and Andreas Heilmann,

owner of a paper mill. It was not until a 1439 lawsuit against Gutenberg

that official record exists; witnesses testimony discussed type, an

inventory of metals (including lead) and his type mold.

Compared to woodblock printing, movable type page setting was

quicker and more durable. The metal type pieces were sturdier and the

lettering more uniform, leading to typography and fonts. The high quality

and relatively low price of the Gutenberg Bible (1455) established the

superiority of movable type, and printing presses rapidly spread across

Europe, leading up to the Renaissance, and later all around the world.

Today, practically all movable type printing ultimately derives from

Gutenberg's movable type printing, which is often regarded as the most

important invention of the second millennium.

Rotary Printing Press

The Rotary Printing Press was invented by Richard March Hoe

in 1843. It uses impressions curved around a cylinder to print on long

continuous rolls of paper or other substrates. Rotary drum printing was

later significantly improved by William Bullock.

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Modern Printing Technology

The folder of newspaper web offset printing press.

Figure (XXX)

Across the world, over 45 trillion pages (2005 figure) are printed

annually. In 2006 there were approximately 30,700 printing companies in

the United States, accounting for $112 billion, according to the 2006 U.S.

Industry & Market Outlook by Barnes Reports. Print jobs that move

through the Internet made up 12.5% of the total U.S. printing market last

year, according to research firm InfoTrend/CAP Ventures.

Offset Press

Offset Printing is a widely used printing technique where the

inked image is transferred (or "offset") from a plate to a rubber blanket,

then to the printing surface. When used in combination with the

lithographic process, which is based on the repulsion of oil and water, the

offset technique employs a flat (planographic) image carrier on which the

image to be printed obtains ink from ink rollers, while the non-printing

area attracts a film of water, keeping the non-printing areas ink-free.

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Currently, most books and newspapers are printed using the

technique of offset lithography. Other common techniques include:

• Flexography used for packaging, labels, newspapers.

• Hot wax dye transfer

• Inkjet used typically to print a small number of books or

packaging, and also to print a variety of materials from high quality

papers simulate offset printing, to floor tiles; Inkjet is also used to

apply mailing addresses to direct mail pieces.

• Laser printing mainly used in offices and for transactional printing

(bills, bank documents). Laser printing is commonly used by direct

mail companies to create variable data letters or coupons, for

example.

• Pad printing popular for its unique ability to print on complex 3-

dimensional surfaces.

• Relief print, (mainly used for catalogues).

• Rotogravure mainly used for magazines and packaging.

• Screen-printing from T-shirts to floor tiles.

Gravure

Gravure printing is an intaglio printing technique, where the image

to be printed is made up of small depressions in the surface of the

printing plate. The cells are filled with ink and the excess is scraped off

the surface with a doctor blade, then a rubber-covered roller presses paper

onto the surface of the plate and into contact with the ink in the cells. The

printing plates are usually made from copper and may be produced by

digital engraving or laser etching.

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Gravure printing is used for long, high-quality print runs such as

magazines, mail-order catalogues, packaging, and printing onto fabric

and wallpaper. It is also used for printing postage stamps and decorative

plastic laminates, such as kitchen worktops.

Digital Printing

Digital printing accounts for approximately 9% of the 45 trillion

pages printed annually (2005 figure) around the world.[8]

Printing at home or in an office or engineering environment is

subdivided into:

• small format (up to ledger size paper sheets), as used in business

offices and libraries

• wide format (up to 3' or 914mm wide rolls of paper), as used in

drafting and design establishments.

Some of the more common printing technologies are:

• blueprint—and related chemical technologies.

• daisy wheel—where pre-formed characters are applied

individually.

• dot-matrix—which produces arbitrary patterns of dots with an

array of printing studs.

• line printing—where pre-formed characters are applied to the paper

by lines.

• heat transfer—like early fax machines or modern receipt printers

that apply heat to special paper, which turns black to form the

printed image.

• Inkjet—including bubble-jet—where ink is sprayed onto the paper

to create the desired image.

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• Xerography—where toner is attracted to a charged image and then

developed.

• Laser—a type of xerography where the charged image is written

pixel by pixel by a laser.

• Solid ink printer—where cubes of ink are melted to make ink or

liquid toner.

Vendors typically stress the total cost to operate the equipment,

involving complex calculations that include all cost factors involved in

the operation as well as the capital equipment costs, amortization, etc. For

the most part, toner systems beat inkjet in the long run, whereas inkjets

are less expensive in the initial purchase price.

Professional digital printing (using toner) primarily uses an

electrical charge to transfer toner or liquid ink to the substrate it is printed

on. Digital print quality has steadily improved from early colour and

black & white copiers to sophisticated colour digital presses like the

Xerox iGen3, the Kodak Nexpress, the HP Indigo Digital Press series and

the InfoPrint 5000. The iGen3 and Nexpress use toner particles and the

Indigo uses liquid ink. The InfoPrint 5000 is a full-colour, continuous

forms inkjet drop-on-demand printing system. All handle variable data

and rival offset in quality. Digital offset presses are also called direct

imaging presses, although these presses can receive computer files and

automatically turn them into print-ready plates, they cannot insert

variable data.

Small press and fanzines generally use digital printing. Prior to the

introduction of cheap photocopying the use of machines such as the spirit

duplicator, hectograph, and mimeograph was common.

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3.3.5 Animation

Animation is the technique in which each frame of a film is

produced individually, whether generated as a computer graphic, or by

photographing a drawn image, or by repeatedly making small changes to

a model unit (see claymation and stop motion), and then photographing

the result with a special animation camera. When the frames are strung

together and the resulting film is viewed at a speed of 16 or more frames

per second, there is an illusion of continuous movement (due to the

persistence of vision). Generating such a film is very labor intensive and

tedious, though the development of computer animation has greatly sped

up the process.

File formats like GIF, QuickTime, Shockwave and Flash allow

animation to be viewed on a computer or over the Internet.

Because animation is very time-consuming and often very

expensive to produce, the majority of animation for TV and movies

comes from professional animation studios. However, the field of

independent animation has existed at least since the 1950s, with

animation being produced by independent studios (and sometimes by a

single person). Several independent animation producers have gone on to

enter the professional animation industry.

Limited animation is a way of increasing production and

decreasing costs of animation by using "short cuts" in the animation

process. This method was pioneered by UPA and popularized by Hanna-

Barbera, and adapted by other studios as cartoons moved from movie

theaters to television. Although most animation studios are now using

digital technologies in their productions, there is a specific style of

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animation that depends on film. Cameraless animation, made famous by

moviemakers like Norman McLaren, Len Lye and Stan Brakhage, is

painted and drawn directly onto pieces of film, and then run through a

projector.

While motion picture films have been around for more than a

century, film is still a relative newcomer in the pantheon of fine arts. In

the 1950s, when television became widely available, industry analysts

predicted the demise of local movie theaters]. Despite competition from

television's increasing technological sophistication over the 1960s and

1970s such as the development of colour television and large screens,

motion picture cinemas continued. In fact with the rise of television's

predominance, film began to become more respected as an artistic

medium by contrast due the low general opinion of the quality of average

television content the 1980s, when the widespread availability of

inexpensive videocassette recorders enabled people to select films for

home viewing, industry analysts again wrongly predicted the death of the

local cinemas.

In the 1990s and 2000s the development of digital DVD players,

home theater amplification systems with surround sound and subwoofers,

and large LCD or plasma screens enabled people to select and view films

at home with greatly improved audio and visual reproduction. These new

technologies provided audio and visual that in the past only local cinemas

had been able to provide: a large, clear widescreen presentation of a film

with a full-range, high-quality multi-speaker sound system. Once again

industry analysts predicted the demise of the local cinema. Local cinemas

will be changing in the 2000s and moving towards digital screens, a new

approach which will allow for easier and quicker distribution of films (via

satellite or hard disks), a development which may give local theaters a

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reprieve from their predicted demise. The cinema now faces a new

challenge from home video by the likes of a new High Definition format,

Blu-ray, which can provide full HD 1080p video playback at near cinema

quality .Video formats are gradually catching up with the resolutions and

quality that film offers, 1080p in Blu-ray offers a pixel resolution of

1920×1080 a leap from the DVD offering of 720×480 and the paltry

330×480 offered by the first home video standard VHS

The maximum resolutions that film currently offers are 2485×2970

or 1420×3390, UHD, a future digital video format, will offer a massive

resolution of 7680×4320, surpassing all current film resolutions. The only

viable competitor to these new innovations is IMAX which can play film

content at an extreme 10000×7000 resolution.

Despite the rise of all new technologies, the development of the

home video market and a surge of online copyright infringement, 2007

was a record year in film that showed the highest ever box-office grosses.

Many expected film to suffer as a result of the effects listed above but it

has flourished, strengthening film studio expectations for the future.

3.3.6 Photography

Photography (pronounced /fәˈtɒɡrәfi/) is the process, activity and

art of creating still or moving pictures by recording radiation on a

sensitive medium, such as a photographic film, or an electronic sensor.

Light patterns reflected or emitted from objects activate a sensitive

chemical or electronic sensor during a timed exposure, usually through a

photographic lens in a device known as a camera that also stores the

resulting information chemically or electronically. Photography has many

uses for business, science, art, and pleasure.

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The word "photograph" was coined in 1839 by Sir John Herschel

and is based on the Greek φῶς (phos) "light" and γραφή (graphé)

"representation by means of lines" or "drawing", together meaning

"drawing with light".Traditionally, the products of photography have

been called negatives and photographs, commonly shortened to photos.

Function

The camera or camera obscura is the image-forming device, and

photographic film or a silicon electronic image sensor is the sensing

medium. The respective recording medium can be the film itself, or a

digital electronic or magnetic memory.

Photographers control the camera and lens to "expose" the light

recording material (such as film) to the required amount of light to form a

"latent image" (on film) or "raw file" (in digital cameras) which, after

appropriate processing, is converted to a usable image. Digital cameras

use an electronic image sensor based on light-sensitive electronics such

as charge-coupled device (CCD) or complementary metal-oxide-

semiconductor (CMOS) technology. The resulting digital image is stored

electronically, but can be reproduced on paper or film.

The movie camera is a type of photographic camera which takes a

rapid sequence of photographs on strips of film. In contrast to a still

camera, which captures a single snapshot at a time, the movie camera

takes a series of images, each called a "frame". This is accomplished

through an intermittent mechanism. The frames are later played back in a

movie projector at a specific speed, called the "frame rate" (number of

frames per second). While viewing, a person's eyes and brain merge the

separate pictures together to create the illusion of motion.

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In all but certain specialized cameras, the process of obtaining a

usable exposure must involve the use, manually or automatically, of a

few controls to ensure the photograph is clear, sharp and well illuminated.

The controls usually include but are not limited to the following:

Many other elements of the imaging device itself may have a

pronounced effect on the quality and/or aesthetic effect of a given

photograph; among them are:

• Focal length and type of lens (telephoto or "long" lens, macro,

wide angle, fisheye, or zoom)

• Filters placed between the subject and the light recording material,

either in front of or behind the lens

• Inherent sensitivity of the medium to light intensity and

colour/wavelengths.

The nature of the light recording material, for example its

resolution as measured in pixels or grains of silver halide. Exposure

and rendering

Camera controls are inter-related. The total amount of light

reaching the film plane (the "exposure") changes with the duration of

exposure, aperture of the lens, and on the effective focal length of the lens

(which in variable focal length lenses, can force a change in aperture as

the lens is zoomed). Changing any of these controls can alter the

exposure. Many cameras may be set to adjust most or all of these controls

automatically. This automatic functionality is useful for occasional

photographers in many situations.

The duration of an exposure is referred to as shutter speed, often

even in cameras that don't have a physical shutter, and is typically

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measured in fractions of a second. Aperture is expressed by an f-number

or f-stop (derived from focal ratio), which is proportional to the ratio of

the focal length to the diameter of the aperture. If the f-number is

decreased by a factor of , the aperture diameter is increased by the

same factor, and its area is increased by a factor of 2. The f-stops that

might be found on a typical lens include 2.8, 4, 5.6, 8, 11, 16, 22, 32,

where going up "one stop" (using lower f-stop numbers) doubles the

amount of light reaching the film, and stopping down one stop halves the

amount of light.

Exposures can be achieved through various combinations of shutter

speed and aperture. For example, f/8 at 8 ms (1/125th of a second) and

f/5.6 at 4 ms (1/250th of a second) yield the same amount of light. The

chosen combination has an impact on the final result. The aperture and

focal length of the lens determine the depth of field, which refers to the

range of distances from the lens that will be in focus. A longer lens or a

wider aperture will result in "shallow" depth of field (i.e. only a small

plane of the image will be in sharp focus). This is often useful for

isolating subjects from backgrounds as in individual portraits or macro

photography. Conversely, a shorter lens, or a smaller aperture, will result

in more of the image being in focus. This is generally more desirable

when photographing landscapes or groups of people. With very small

apertures, such as pinholes, a wide range of distance can be brought into

focus, but sharpness is severely degraded by diffraction with such small

apertures. Generally, the highest degree of "sharpness" is achieved at an

aperture near the middle of a lens's range (for example, f/8 for a lens with

available apertures of f/2.8 to f/16). However, as lens technology

improves, lenses are becoming capable of making increasingly sharp

images at wider apertures.

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Image capture is only part of the image forming process.

Regardless of material, some process must be employed to render the

latent image captured by the camera into a viewable image. With slide

film, the developed film is just mounted for projection. Print film requires

the developed film negative to be printed onto photographic paper or

transparency. Digital images may be uploaded to an image server (e.g., a

photo-sharing web site), viewed on a television, or transferred to a

computer or digital photo frame

A photographer using a tripod for greater stability during long exposure

Figure (XXXI)

Prior to the rendering of a viewable image, modifications can be

made using several controls. Many of these controls are similar to

controls during image capture, while some are exclusive to the rendering

process. Most printing controls have equivalent digital concepts, but

some create different effects. For example, dodging and burning controls

are different between digital and film processes. Other printing

modifications include:

• Chemicals and process used during film development

• Duration of print exposure – equivalent to shutter speed

• Printing aperture – equivalent to aperture, but has no effect on

depth of field

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• Contrast – changing the visual properties of objects in an image to

make them distinguishable from other objects and the background

• Dodging – reduces exposure of certain print areas, resulting in

lighter areas

• Burning in – increases exposure of certain areas, resulting in darker

areas

• Paper texture – glossy, matte, etc

• Paper type – resin-coated (RC) or fiber-based (FB)

• Paper size

• Toners – used to add warm or cold tones to black and white prints

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