Difference between GRACoL, GRACoL 7 and G7
The terms “GRACoL” “GRACoL 7” and “G7”, tend to be used interchangeably even though they have very different meanings!
GRACoL®, in the generic sense, refers to the Idealliance Committee that began in 1996 as a graphics arts task force that was formed to develop a document containing general guidelines and recommendations that could be used as a reference source across the industry for quality color printing. The mission of GRACoL is to improve communications and education in the graphic arts by developing best practices that reflect the influence and impact of new technologies in the workflow of commercial offset lithography. GRACoL is a registered trademark of Idealliance.
GRACoL 7 is the current version of the GRACoL Publication. The GRACoL 6 Guidelines was published in 2002. Since that time, the Idealliance GRACoL Committee conducted a series of research press runs and developed a new set of process controls based on principles of digital imaging, spectrophotometry, and computer-to-plate (CtP) technologies in ways that have not been done previously in the US. GRACoL 7 will explain the rationale behind the new visual-appearance-based GRACoL press and proofing system, gray balance characterization and calibration methods. In addition, GRACoL 7 will specify a definition for gray balance and recommend characterization data for commercial offset printing on a #1 coated sheet. These recommendations are intended to stabilize visual output but not to eliminate process control best practices based on SIDs or TVI/Dot Gain as defined in the ISO 12647-2 printing standard.
G7™, the Idealliance proof-to-print process, is based on principles of digital imaging, spectrophotometry, and computer-to-plate (CtP) technologies. G7 is currently being applied to many types of printing including commercial and publication printing, newsprint and even flexo. This new methodology utilizes the existing ISO 12647 Standards as the basis for good printing. G7 requires printing with inks defined by ISO 2846-1 so that the dry solids measure as close as possible to the ISO CIELab values for seven colors ?the four primary colors and three 2-color overprints specified in ISO 12647. Because our goal is to specify a simple calibration process that will help the printers reliably achieve a close “visual match” from proof to press, G7 breaks from tradition by focusing on colorimetric data for gray balance in the mid-tones rather than on densitometric aims, i.e. dot gain, for each color. G7 is named for its gray scale calibration technique and the 7 ISO ink colors it requires. G7 is a trademark of Idealliance. Although G7 was developed by the efforts of the GRACoL Committee, it should not be confused with GRACoL or with GRACoL 7.