What is G7?
G7 is an innovative calibration specification developed by IDEAlliance to modernize and improve the latest versions of GRACOL™ (Graphic Requirements for Applications of Commercial Offset Lithography) and SWOP™ (Specifications for Web Offset Publications). IDEAlliance is promoting the G7 method as a constant component of all future print specifications, and has offered it openly for adoption by all standards associations for all types of imaging or media, worldwide. The main purpose of G7 is to simplify the calibration of any printing device (such as a pre-press proofing system or printing press) to the IS0 12647-2 printing standard. The -2 at the end of the specification designates “Litho” but G7 can be applied to any type of printing that uses a CMYK color space, regardless of what inks are used or how the ink is put on paper.

Common Misunderstandings

1. G7 is not for Screen Printers or Digital Printers.
   Actually it is and NCS has calibrated and certified screen printers and has attained G7 Certified Results on many Digital Printing devices.
2. A common misunderstanding is that G7 is an official standard.
   G7 is NOT a standard. It is a specification of a calibration methodology designed to attain the gray scale appearance implied in the ISO 12647‐2 standard, while by‐passing the ambiguous and visually-inconsistent TVI (dot gain) definitions in the current standard documents.

G7 adjusts the device via typical CMYK RIP curves, or other device calibration utilities, to match a pre-defined NPDC (Neutral Print Density Curve) and gray balance. G7 assumes the use of ISO-standard inks, for which precise L*a*b* values are defined in ISO 12647-2, but even if your device uses non-ISO inks (different color) G7 calibration will give CMYK prints the same “natural” gray scale appearance as the results from all other G7 devices. The secret of the G7 method is that the results of a constant “appearance” in terms of gray balance and neutral density are specified, not the elements of the appearance. Therefore regardless of what colorants you use or how they are applied to the substrate, without the need for additional color management the appearance spec is constant. G7 is therefore the first calibration methodology to offer cross-media gray scale consistency, which means files are more easily and safely re‐purposed. While G7 alone does NOT attempt to control color accuracy, the fact that it does control neutral gray tones, without ICC profiles, is a major step towards a universal standardized definition of printed “appearance” that can be applied to all imaging methods.