electronic work flow chapter 13 © goodheart-willcox co., inc.permission granted to reproduce for...

Electronic Work Flow

Chapter 13

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.

Objectives

Distinguish between analog form and digital form.State the functions of word processing, page composition, and illustration programs.Explain the functions of PDLs.Summarize the functions of Print Production Format (PPF) and Job Definition Format (JDF).


Objectives

Cite the definition of preflighting and explain its importance to prepress production.Describe the basic creation, transmission, and output of electronic media.List proofing methods used in the printing industry.


Objectives

Identify the basic functions of raster image processors (RIPs), imagesetters, and platesetters.Define digital printing.


Analog vs. Digital

Most images enter the work flow in analog form and are converted to digital formAnalog images are continuous and can vary in densityDigital images consist of cells on a grid (pixels)


The Transition to Digital

Image reproduction was originally limited to type and black-and-white line drawingsInvention of photography in the 1800s made it possible to capture photographic imagesReproducing these images was not possible until the invention of the halftone screen in 1886Electronic scanners and digital cameras are used now


Computer Platforms

Major ones in use today:– PC– Macintosh computer

Defined by operating system used

Many service bureaus use a particular platform

Cross-platform programs, formats, or devices work on different platforms


Software Programs

Used for many applications in the printing industry

Text creation and editing are done in word processing programs

Text can be imported into a page composition program

Other software is used for image creation and manipulation and imposition


Paint Programs

Create or transform images into bitmap graphicsBitmap graphic—pattern of pixels arranged on a gridNumber of bits in a pixel is the bit depth

One-Bit Pixels Eight-Bit Pixels


Draw Programs

Use straight and curved lines to produce vector graphics

Vector graphics are represented as mathematical formulas– Can be greatly enlarged

and still remain sharp– Require less computer

memory than bitmap files


Image Manipulation Programs

Paint programs that generate bitmap graphics

More advanced programs allow manipulation of almost any aspect of an image– Cropping images– Changing color and contrast– Removing and replicating images


Page Composition Programs

Integrate files produced by very different types of softwareUnderstand different languages used and translate elements into a common language


Translating Files

PDL directs imaging performed by the output devices

Interpreters translate PostScript page descriptions line by line into patterns of dots or pixels

Encapsulated PostScript (EPS) files include low-resolution representations of documents


Portable Document Format (PDF)

Evolved out of PostScript technology

Designed to support:– CD-ROMs– Internet- and intranet-page production– Digital-printing technologies– Digital work flow of

computer-to-plate (CTP) technology

A good preflighting tool


Integrating All of Production

International Cooperation for Integration of Prepress, Press, and Postpress (CIP3) was created to reduce compatibility problems

CIP3 produced Print Production Format (PPF)

PPF evolved into Job Definition Format (JDF)


Desktop Publishing

Basis for all electronic prepress

Used to produce art, copy, and page composition

Pages are output as laser proofs

Corrected files are translated to PostScript format and sent to printer


Stages of Electronic Prepress


Power Supply

When electrical power supply is disrupted, digital work flow is halted

An uninterruptible power supply saves time and prevents work-flow interruptions

Desktop computers can use a small battery supply

Some uninterruptible power-supply systems protect from power surges


Service Bureaus

Contracted by publishers to scan high-resolution images or output film

Provide link between publishers or ad agencies and printers

Some offer a full range of prepress services

Output service bureaus limit their services to high-resolution output from PostScript files


File Formats

Attention must be paid to the format in which data is stored

Text files can be saved in various formats and reformatted for use in other programs

Graphic image formats are not as flexible


Caution

Digital data can become damaged or corrupted

Always back up your files on a regular basis

When you make backup copies, you are copying your files to a second medium as a precaution, in case the first medium fails or is destroyed


File-Naming Conventions

Carefully naming files keeps work organized– File names should not begin with a space– Each file name should be unique– Only alphanumeric characters should be used– Appropriate file extensions should be used

Automatic picture replacement (APR) files should not be renamed because the name of the file links to high-res image


Preflighting

Orderly review of files to identify problems:– No laser proofs supplied

– Incorrect page sizes

– Inadequate image bleeds

– Scans supplied in wrong file format

Scitex Graphic Arts Users Association (SGAUA) publishes the Computer Ready Electronic File (CREF) II guidelines


Preflighting Chart


Preflighting Chart (Cont.)


Checklist for Materials


File Repair

Digitally send files to a data-repair and -recovery service

Purchase file-repair software– Repairs certain film formats, media, or

application files– Recovers graphics files that were

accidentally deleted


Monitors

Software used for word processing and page layout provides a What You See Is What You Get (WYSIWYG) display

Color-management software provides a What You See Is What You Print (WYSIWYP) display

Resolution and dot pitch are important


Types of Monitors

Cathode-ray tube (CRT) monitors– Images are generated from beams of electrons

striking phosphors on inside of screen

Liquid crystal display (LCD) monitors– Consist of a coating of liquid crystals between two

thin sheets of polarized glass

Plasma display monitors– Cells containing plasma are activated by a small

electric current


CRT Monitors


LCD Monitors


Plasma Display Monitors


Types of Printers

Dot matrix printers

Ink-jet printers

Laser printers

Thermal printers

Dye sublimation printers


Types of Ink-Jet Printers

Drop-on-demand ink-jet printers– Thermal ink-jet printers– Piezoelectric ink-jet printers

Continuous ink-jet printers– Emit a steady stream of droplets that

receive electrical charges– Designed more for speed than image

quality


Thermal Ink-Jet Printers


Piezoelectric Ink-Jet Printers


Laser Printers


Engine Speed

Maximum number of pages the printer can output in full- or single-color mode

Measured in pages per minute


Caution

Some ink-jet and laser printers use agents that can be irritating or toxic

Laser toner can be an irritant to the respiratory tract and eyes

MSDSs are available from the toner vendor or manufacturer


Types of Proofs

Hard proofs

Soft proofs

Digital proofs

Contract proofs


Proofing

Customers often require proofs that accurately represent color and halftone reproduction

Digital-proofing systems can simulate the dot gain expected on press

Remote proofing allows a printer to send digital files to out-of-town clients


Imagesetters


Types of Imagesetters


Imagesetter Calibration

Ensures high-quality output and repeatability

Imagesetter maintenance is important


Platesetters

Eliminate the need for film by exposing directly to plate material

Categories:– Flatbed platesetters– Internal-drum platesetters– External-drum platesetters


Imagesetting Systems

Consist of imagesetter and raster image processor (RIP)

RIP translates language of page-layout software into language of imagesetters and platesetters

Conversion of vector images to raster images is rasterization

Interpreter in the hardware converts files


RIP Conversion


Automated Ink Control

In the past, ink keys were manually set to ensure that areas of the plate received the right amount of ink

In the 1900s, plate scanners were developed, which set ink controls automatically

Now, digital data from the RIP can also set the ink keys automatically


Digital Printing

Any method of printing in which imaging of the plate occurs on press

Includes two processes:– Digital imaging (DI) technology

• Advantages are shorter production time, reduced labor costs, cost-effective short runs, and greater registration control

– Digital toner-based press technology• Main advantage is variable data printing (VDP)


The Internet

Used to communicate, transfer documents, and sell products and services

Originally developed for the military

Fastest growing part is the World Wide Web (WWW)


Review Questions

What is the main difference between analog form and digital form?

Analog images are continuous and can vary in density, while digital images consist of tiny cells on a very fine grid.


Review Questions

Text creation and editing should be done in a(n) _____ program.

word processing


Review Questions

What is the main function of a PDL?

A PDL directs the imaging that an output device performs.


Review Questions

PPF evolved into _____, which is a standard method of communication that eliminates the need for data to be reentered as a job moves from one system to another during production.

Job Definition Format (JDF)


Review Questions

What do we call the orderly review of files to identify potential problems that could occur during production?

Preflighting


Review Questions

Which of the following types of printers operates very similarly to photocopying machines?

A. Dot matrix printer

B. Dye sublimation printer

C. Ink-jet printer

D. Laser printer

D. Laser printer


Review Questions

What is the difference between hard proofs and soft proofs?

Hard proofs are tangible sheets of paper made directly from digital files, while soft proofs are the images displayed on a computer monitor.


Review Questions

A(n) _____ is a high-resolution output device that takes bitmap data generated by a RIP and writes it to film, paper, or printing plates, using a laser that writes the data line by line.

imagesetter


Review Questions

What is digital printing?

Any reproduction technology that receives electronic files and uses spots (or dots) for replication.

electronic work flow chapter 13 © goodheart-willcox co., inc.permission granted to reproduce for...

Documents

educational use

images slide

imposition slide

page composition programs

digital printing

common language slide

platform programs

advanced programs