New specification also introduced for specific requirements of labels and packaging.
Belgium : The Ghent Workgroup (GWG) is releasing its milestone GWG2015 PDF Specification for print and packaging production.
Built by graphic arts and PDF experts, the new GWG2015 PDF Specification describes file setting and workflow processing requirements for the highestquality production and exchange of PDF files, according to the group.
Compliance with the new specification guarantees quality consistency across the supply chain up to printing and publishing, said GWG.
Founded in 2002, the Ghent Workgroup is an international assembly of industry associations and suppliers from across Europe and the United States. The group has produced many process specifications for PDF exchange and developed tools for automating processes and testing to establish consistent PDFs for quality print and publishing.
The GWG2015 Specification is built on the modern ISO PDF/X-4 standard and adds specific requirements for different market segments, called variants. The variant “family” covered by the GWG2015 PDF Specification is heatset and coldset printing. It includes more conservative variants restricted to the use of CMYK and more progressive variants allowingwider gamut colour spaces for image content.
GWG has also announced its GWG2015 PDF Specification for Packaging. Created by its packaging committee, this addresses offset, gravure and flexo. Leading the creation of this specification were the chairs of the packaging committee, Christian Blaise from bleuprocess, Steve Carter from PhotoType and Lieven Plettinck of Esko.
“Because of the unique requirements inherent in the process, we needed to develop a dedicated PDF Specification for packaging,” said GWG. “Built upon the ISO PDF/X-4 standard, the GWG2015 PDF Specification for Packaging meets that need and addresses the specific issues relevant to package and label production.”
GWG chairman David Zwang said the new specifications were developed “to keep up with the changing state of technology and the market demands”.
“The significant change in the 2015 specification was related to what constitutes the safe colour spaces and conditions that can be used for reliable reproduction,” he said. “In addition, there were other minor changes that are designed to address user feedback on the GWG2012 specifications.”
Within the GWG2015 PDF Specification, the GWG defines guidelines for different market segments, output processes or workflows. Practical examples include the colour spaces allowed in a PDF file, or the image resolution required for images in a particular type of workflow. PDF Specifications also feature page and text scaling, overprint, and ink coverage, as well as ICC profile usage.
The GWG is also providing documentation with its new specifications including an implementation guideline and a document on the differences from GWG 1v4 specifications.
GWG executive director David van Driessche, who co-authored the documents, said, “The documentation should help users understand which specifications to use and what impact the changes in those specifications may have on their workflows.”
The major changes from GWG 1v4, which was based on the PDF/X-1a ISO standard, are centred on a few areas. One eases restrictions for use of ICC profiles and certain colour spaces, depending on whether the restrictions are being applied to continuous tone images. Van Driessche said some variants of the 2015 Specification allow calibrated RGB, ICC-based RGB and LAB colour spaces for some print elements: “this allows for much more flexible workflows, but also constitutes a major change”.