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PDF: The Cure for Dawdling Digital Files

(December 1999) posted on Tue Dec 14, 1999

Learn the basics of creating PDF files.

click an image below to view slideshow

By Mark A. Coudray


6. Print the graphic to a PostScript file, or, if your computer has sufficient resources, distill the file to PDF directly from the illustration program.


7. If the original file is saved as PostScript code, open the file in Distiller and convert to PDF based on the settings you established in steps 2-4.


8. View, proof, and print the PDF file.


PDF is rooted with the service bureau, where digital technicians have wrestled with digital files for many years. The conventional, non-PDF approach involves converting a file into PostScript code, which is sent to the RIP (Raster Image Processor). The RIP then processes and sends the layers of type, elements, and imbedded graphics (generally EPS, TIFF, JPEG, or nested EPS images) contained within the graphic to the output device. But the complex nature of layered graphic files often causes the RIP to choke and dump the files--usually an hour or more into the process, and most often when we were on deadline.


To help reduce this problem, Adobe introduced Distiller, a program designed to "distill" out redundant PostScript code from files. This streamlines files and reduces their size. The resulting code is called "clean code" because it slips cleanly through the RIP to the imagesetter or output device. Today, Distiller is the primary engine of the PDF workflow and one of four programs in the Adobe Acrobat family for managing PDF files.


PDF and graphics


While the vast majority of documents published in PDF take the form of manuals and on-line business forms (all government forms are PDF format, for example), the use of PDF as a high-end digital-prepress vehicle is relatively new. But as more and more service bureaus install and upgrade to PostScript 3, a key component of the PDF workflow, the capabilities of PDF technology will become much more common. Let's take a look at the specific benefits and concerns PDF introduces.


We'll start with fonts. PDF provides two different font options. The first is embedding fonts and the second is subsetting fonts. To take advantage of embedding, we must use either Type 1 PostScript or TrueType fonts. These fonts are known as outline fonts because they are represented by an outline that can be scaled to any required size and then filled.



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