PRINTING PRESS WORKFLOW | A COMPREHENSIVE GUIDE | By: Rodelio D. Balagot
| ARCHIVE DIRECTORY | PREPRESS FLOWCHART | PRINTING PRESS FLOWCHART | PREPRESS & PRINTING TROUBLESHOOTING |
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Printing Press Workflow Chart |
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Printing Press Workflow |
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A workflow consists of a sequence of connected steps where each step follows without delay or gap and ends just before the subsequent step may begin. It is a depiction of a sequence of operations, declared as work of a person or group, an organization of staff, or one or more simple or complex mechanisms. Workflow may be seen as any abstraction of real work. For control purposes, workflow may be a view of real work in a chosen aspect, thus serving as a virtual representation of actual work. The flow being described may refer to a document or product that is being transferred from one step to another. The concept of workflow is closely related to several fields in operations research and other areas that study the nature of work, either quantitatively or qualitatively, such as artificial intelligence (in particular, the sub-discipline of AI planning) and ethnography. The term workflow is more commonly used in particular industries, such as printing and professional domains, where it may have particular specialized meanings.
Between the invention of the printing press and that of the computer, developments in printing and publishing technology occurred in small increments over long periods of time. In those intervening centuries, the process of preparing manuscripts for publication remained fairly static. In the last half-century, however, the pace of change in printing and publishing technology has become dynamic. Now changes in technology come about in a matter of years, sometimes even months. And with those changes, the steps in the process of publication may now be controlled, tracked, and subsumed into one continuous electronic system often called digital workflow. Scholarly publishing encompasses six major functions:
Over the years publishers have incorporated discrete automation applications for these major functions. Now scholarly publishers can create a workflow linking all the steps in a completely digital process. This white paper presents a snapshot of current technologies used throughout publishing and printing. Over the past 30 years, computers have changed procedures for preparing publications dramatically. First, photocomposition replaced hot type, but layout artists still pasted up pages, often using decorative tapes and markers to create illustrations. Gradually, the industry moved to creating pages in the computer; printers worked from sheets of resin-coated paper or even film generated by imagesetters. With the advent of desktop publishing programs, publishers began supplying disks to printers; however, advertising and many illustrations remained separate, often on hard copy. Today publishers can prepare fully integrated digital files containing all content (illustrations, text, and advertising) that printers can receive. The 1990s brought rapid developments in printing technologies, publishing software, computer applications, and the Internet, that facilitate the flow of information from author to reader. These new technologies present several options for scholarly publishers and their partners engaged in the manufacture, storage, preservation, and retrieval of information. Implementing a digital workflow can result in streamlined processes, increased quality, and potential for lowering internal cost structure. Composition and PrepressUsing coded and edited files, the compositor or printer integrates text, black and white art, and color images. Several platforms and programs may be used depending on the project. There are traditional typesetting systems such as Miles, Penta, and Xyvision; and there are desktop programs such as QuarkXPress, PageMaker, or FrameMaker. Acquiring usable digital art is still one of the more challenging technical aspects of the composition process. Digital Proofing Definition Proofs created directly from electronic page layouts to enable full digital workflows with no film. Digital proofs, sometimes called soft proofs, are also used in the composition cycle. Process Digital pages are transferred to a digital proofer, which reproduces the page using imaging software to interpret the binary data in the file. Digital proofers include:
The development of digital proofing equipment that produces a halftone dot significantly advanced digital workflow. The halftone dots permit accurate calibrations and checking ink trap, which previously had been accomplished with analog proofs made from film. Until halftone dots were available, many publishers were hesitant to trust digital proofs. The large format proofer enables printers to produce an entire imposed signature and later fold it down to represent the pages of a book or journal. This process replicates the traditional blueline, except that no film is used. High-end color digital proofers are becoming fairly common. It is important to use International Color Consortium color profiles for calibration, so that all applications are using a standard color language to interpret the colors. DuPont Digital WaterProof, Fuji FirstProof, Iris proofers, Kodak Approval, and Polaroid Polaproof are among the most common proofs for high-resolution digital proofing of four-color work. For black and white materials, there are inkjets and a variety of laser proofs. Digital bluelines that show full color replace conventional Dylux proofs. Prepress production processes begin with preflight checking that entails opening each file to ensure that all parts of a manuscript will reproduce properly. A preflight checklist must be examined and approved before a publication is released for printing and distribution. Preflight Definition Process of completely checking digital files against an extensive checklist of items to ensure correctness before releasing publication to printing. Checklist The items examined during preflight include fonts, graphics, text and page construction, margins and folios, proper file-building techniques, color, and proofing issues. Process Preflighting files is absolutely necessary to ensure quality control and an effective digital workflow. Preflighting takes place at the end of the composition process and again before plates are produced. As suppliers receive files from customers, they run them through preflighting checks to assure that they are usable. Three types of checks detect file errors. Those are application file preflights, which are most time intensive; PostScript file preflights, which require special analysis software; and PDF file preflights, which also require special software. Examples of software used include Acquired Knowledge Download Mechanic, Enfocus PitStop, Extensis PreflightPro, and Markzware Flightcheck. Following preflight, some additional steps are required to prepare the publication for online distribution. The document may be rendered in HTML for viewing on the Web. If PDF files were not used for plate output, they will be created at this stage so the reader can print the publication from the Web files. Definition PDF or Portable Document Format is an Adobe format derived from their PostScript language. An object-oriented file format that is platform independent, it combines the strength of PostScript with some of the flexibility of application files. Process Developed in the early 1990s, PDF made it possible to create an electronic file that could be sent to many different computers that did not use the same operating systems or applications. Adobe added features that made PDF usable for high-end graphic applications, as well as desktop, office, and Web processes. Once a document has been created in PostScript, it is "distilled" into PDF using Adobe Acrobat Distiller or PDFWriter, which creates low-resolution PDFs from common software programs. It is also possible to generate PDFs directly from application files such as Adobe InDesign. In the Adobe 4.0 version, users have three options when preparing a file for printing:
For example, PDF files can serve as e-page proofs sent to the author and editor instead of traditional laser proofs. Recipients can print them out and fax back corrections, or they can use Adobe Acrobat to make revisions directly in the PDF proof file. In the last stage of page composition, PDFs can substitute for traditional PostScript for film or plate output. The same files distilled for film or plate can be distilled again for low-resolution Internet-compatible PDFs. Benefits PDF offers a number of benefits in the digital workflow:
PrintingOnce the printer has verified that the files are accurate and complete, they are ready to make a plate to use on the press. In a less fully digitized environment, the preflighted disk is used to create signature impositions, which are sent to an imagesetter to produce film. Disk to Film Definition Film derived from an imagesetter controlled by computers. This process is digital from page composition to imagesetting, and it may have been digital from the authors creation through the content shaping and polishing to page composition. The digital workflow is truncated, however. Instead of going all the way through platesetting and printing, it terminates with film. Process First, the compositor creates pages using one of the various page composition programs. All of the necessary graphic elements are integrated or gathered and sent to the printer with the composition files. Page files are preflighted to determine if they will yield good high-resolution PostScript. Fonts and graphics are embedded, and Post-Script files or PDFs are created. They are then preflighted for data integrity. Next they are imposed using imposition software to create signature templates. That is, the pages are put in the correct order for printing, folding, and binding. These imposition signatures generally contain four, eight, or sixteen pages; however, signatures vary depending on the printing press. The signatures are then sent to the imagesetter, which generates plate-ready film in the correct page order and position for printing. In a more fully digitized workflow, the printer produces a plate directly from the files. Getting to press with a computer to plate process can be faster than it is with film. Computer to Plate Definition Computer to Plate (CTP) is the process by which lithographic printing plates are imaged directly from digital files. Process The CTP process starts with the preparation of files during the page creation stage and finishes with digitally imaged plates. Preparing Files Postscript files of each page are digitally arranged in the order they will appear on the plate during a process called imposition. Specialized software, such as ImposeIt from IPTech or PREPS from ScenicSoft, or vendor-specific imposition software is used. Then the files are RIPed (Raster Image Processed), and color trapping may occur. Once the files are imposed, trapped, and RIPed, they are ready for imaging. Imaging Feeding can occur manually or automatically. Generally, automatic plate feeding is used in visible light platesetters, which must be run in a darkroom environment. Thermal plates, which can be handle under normal light conditions, allow more flexibility for manual or automatic feed. Two types of technology may be used during this process: internal drum or external drum. In internal drum systems, laser signals are sent to a spinning mirror, which reflects light onto a stationary plate to expose it. In external systems, the drum holding the plate rotates while a stationary bank of laser diodes expose the plate. Processing The plate must be processed after exposure. Chemicals are applied to the plate during this final step and the plate comes out of the processor ready for the printing press. But many publishers and printers must still contend with film, either because it is supplied for advertising or because they are using archived film. A process called copydot scanning can help them move from film to computer to plate production. Copydot Film Scanning Definition A process that scans film, digitizes the data, and creates a bitmap file ready for the RIP. Process Using copydot scanners, printers scan color-separated halftone film to create digital files that can be integrated into a totally digital workflow. Although the digital file is another generation, the material has been scanned at a high resolution such as 4800 dpi; consequently, little or no data is lost. Copydot scanning can help publishers move from film, supplied or archived, into computer to plate production. Copydot scanning is an interpretive process that requires expensive specialized equipment to create a third generation file of a second generation image (film). Copydot scanners and software vary in quality; consequently, quality variations may occur in the outcome, depending on the equipment used.
Computer to press is the most dramatic printing advance to date in the quest for an all-digital workflow that culminates in putting real ink on paper. The process eliminates a separate platesetting device, and relies on highly specialized printing technology called Direct Image (DI) presses. Computer to Press Definition Computer to Press is a lithographic printing process in which plates are imaged directly from digital files while the plates are positioned on the plate unit of the printing press. The Press This process requires a specialized offset printing press called a Direct Image (DI) press that incorporates imaging heads, printing plates, and a common impression cylinder. Alonso (1998) described the Direct Image presses as machines that combine traditional offset technology with "on-press imaging functionality." The press uses real printing ink, rather than toner. The plate relies on waterless technology, and the ink pools inside the recessed image area in a process similar to gravure. DI presses are one of three types of digital presses. The other two include digital photocopiers and printers that accommodate variable data. Process All proofing and file preparation are completed prior to the imaging process. Bitmapped files are sent to and queued up at the presscomputer station. Clean plates are automatically fed into position, and the plate cylinder begins to spin while a bank of laser diodes image the plate. Once the plate is imaged and cleaned, sheets are run through the press to complete the makeready. When color and registration have been fine-tuned, the job is ready to run. Basically, digital files created by the publisher are used to image the printing plates while the plates are hanging on the press. The combination of digital files and digital presses has made print-on-demand economical. Being able to print very short runs cost-effectively alleviates several problems related to distribution and warehousing and can reduce costs, particularly for non-serial publications. DistributionAutomation has enhanced all the steps in the distribution of publications both in print and electronic form. Bar codes are printed on cartons and skid labels so that the distribution center can process inventory with the wave of a sensor wand. UPC (Universal Product Codes) bar codes are also printed on individual publications to facilitate processing for wholesalers, retailers, and librarians. Automated manifest systems track shipments so that distributors can keep customers informed about delivery. Integrated distribution and fulfillment systems incorporate inventory control, customer databases, order processing and tracking, accounts receivable, sales histories, and so forth. From order entry, these systems automatically deduct from perpetual inventory, update accounts receivable, and feed into all sales history programs. With e-commerce systems linked to publisher's Web sites, the process is even further automated because the customer in effect accomplishes the order entry. For electronic publications, the publisher maintains digital files for access directly by end users or for transfer by telecommunications or magnetic tape to an aggregator for further distribution as part of a larger database. MarketingMarketing professionals have long regarded the computer as a valuable workhorse. They have relied on databases to handle a myriad of tasks such as maintaining customer files and profiles, creating labels and mailing lists, tracking promotion results, and reporting unit and dollar sales. Professional marketers equate the development of database marketing in the 1980s with the new advertising medium television offered in the 1950s (SRA, 1999). Now a flourishing and accepted strategy, database marketing is likely to become the basis for most effective marketing programs in the new century. Swanson Russell Associates (SRA, 1999) outlined steps in the database marketing process, which can be summarized as follows:
Using a digital workflow, a publisher can produce customized marketing materials such as brochures targeted to specific audience segments. Catalogs can be offered in different languages, and advertisements changed for special offers in different venues. Marketing research professionals, long-time users of computer resources for data entry, tabulation, and compilation, have now added online research to the traditional mail survey, in-person or telephone interview, and on-site focus session. There are two major ways of conducting surveys electronically: e-mail and Web-based. Both are in their infancy, but the larger market research firms are attempting to develop their effectiveness and reliability. In both, responses are transferred electronically to the research firm in another example of a completely digital workflow.
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