30 years of Adobe PDF for commercial print

Image source: Adobe Stock/terex.

In 1991, Adobe co-founder John Warnock had a vision: “Documents should be viewable on any display and should be printable on any modern printer.” He boldly predicted: “If this problem can be solved, then the fundamental way people work will change.” Two years later, Warnock’s vision was brought to life when Adobe launched Acrobat 1.0 and published the specs for PDF 1.0. Their universal Portable Document Format continues to transform the world, including the world of commercial print production.

PDF built upon the worldwide success of Adobe’s first technology — the PostScript® Page Description Language (PDL) and RIP (Raster Image Processor). PostScript was a game-changer that revolutionized the graphic arts in the 1980s. The cost of producing print-ready pages plunged, dramatically increasing the volume and quality of all types of printing.

Adobe collaborated with Apple and Microsoft to pre-install PostScript print drivers on 99 percent of the world’s computers. This ubiquity enabled every desktop application to “print” to a PostScript file, which Acrobat could then “distill.” Every class of visual material could be “flash-frozen” inside a PDF file. While Adobe has always made the PDF specification publicly available, since 2008, the specification itself has been managed by the ISO (International Organization for Standardization). PDF is the default for exchanging documents and print jobs, and its use continues to grow in every print segment.

Timing is everything in the adoption of a new technology. The advent of PDF 1.0 converged with the rise of the internet, opening new avenues for exchanging graphically rich final content. PDF files were attached to emails and downloaded from web pages. The launch of PDF also intersected the digital transformation of the print industry — a multi-dimensional convergence of several new technologies:

• GUI layout — Hand-positioning waxed pieces of text and graphics onto artboards gave way to keyboards, mice, and monitors. With new tools like PageMaker running on the Apple Macintosh, designers could visually layout a print job on their computer display.
• Scanned images — Computers were also employed to scan photographs mounted on spinning plexiglass drums from Hell and Crossfield. The resulting color-separated files could be digitally color-corrected and retouched on dedicated workstations.
• CTP platesetters — The labor-intensive craft of half-toning and film stripping film gave way to specialized software and precision laser-powered technologies: full-signature imagesetters from Screen, and platesetters from Creo.
• Inkjet proofing — Inkjet technology from companies like Iris was employed to proof jobs that were created without the use of any film whatsoever.
• Digital printing — In 1993, the same year Adobe launched Acrobat and PDF, the first digital presses from Xeikon and Indigo began challenging the dominance of offset, gravure, letterpress, and flexo printing.

These parallel transformations in prepress and printing raised the urgent need for an electronic method to convey advertisements and print-ready final content — a digital master file. Since visual inspection of physical prepress media was no longer possible, reliability and trust were the top priorities. So, the industry gravitated toward TIFF/IT, which consisted of several pixel-map files: a low-resolution contone file for images and a high-resolution linework file for text and graphics, with separate files for each spot color plate. TIFF/IT supported transparency alpha channels, but the filesets were large, complicated, and required specialized software to view.

When industry experts began investigating PDFs, they quickly realized that they were just as reliable as TIFF/IT. In addition, PDF had some important advantages: self-contained, device-independent, graphically robust, flexible, and with a small file size. One attribute was especially valuable: a PDF job file could be easily displayed on any computer using the free Acrobat Reader.

Graphic artists sent PDF job files to printers, and printing vendors incorporated PDF into their prepress solutions. PDF pages could be easily managed, manipulated, and imposed into signatures. But at the end of the workflow, the PDF files had to be converted to PostScript for final rendering. That all changed in 2006 when Adobe launched the PDF Print Engine. Finally, the benefits of the PDF imaging model, including live transparency, were available from end-to-end across the entire prepress workflow. With 16 different transparency blend modes supported in the RIP, graphic artists could let their imaginations run wild, enabled by new visual effects in authoring tools such as Adobe Illustrator, Adobe Photoshop, and Adobe InDesign.

Early on, print industry experts realized that the incredible power of PDF needed to be tamed. So, they developed PDF/X (eXchange) as an international standard, the first subset of the PDF language to be optimized for specific usage. PDF/X continued to evolve with the addition of various enhancements; the current version is PDF/X-6. Other subset standards were developed, including PDF/VT, a subset optimized for Variable Data Printing (VDP). The main rendering challenge of VDP production is to cache the non-variable elements and retrieve them on subsequent pages when needed. A RIP must avoid redundant processing to drive a digital press at its rated speed when every page is different.

Adobe initiated the development of PDF/VT (Variable, Transactional) to address these requirements, and it became an ISO standard in 2012. With PDF/VT, all the PDF workflow and imaging model benefits became available for personalized print and Variable Product Printing (VPP).

Thirty years after the dawn of the PDF era, the Portable Document Format continues its advance into new print industry segments. For example, textile print is migrating to inkjet, and PDF is beginning to replace image formats such as TIFF. PDF is key to reliable reproduction of graphically rich content on fabric. In every print industry segment, PDF is the best way to follow the guiding principle of digital prepress workflow: maintain graphics at their highest level of abstraction until ink meets substrate.