G7

From ColorWiki

Revision as of 20:12, 13 May 2009 by Patrick (Talk | contribs)
Jump to: navigation, search

G7® is a Specification defined by the Print Properties and Colorimetrics Working Group of IDEAlliance.

G7 is a method for matching color across multiple printing devices, such as printing presses and proofing systems. It can be applied to any printer that has a calibration process (usually involving adjusting color "curves" in a RIP) that allows control over CMYK inks. These would include web presses, sheet-fed presses, proofing systems, inkjet printers being driven by RIPs. The goal of G7 is to provide visually consistent, repeatable color between different devices (like proofers and printers) as well as different presses, and even different facilities. The emphasis in this specification is on gray balance. Since human vision sees differences in gray more readily than more saturated colors, this specification is more likely to result in successful visual "matching" than merely matching solid ink densities which is typically done for more traditional standards.

Note that G7 is a specification - not a standard. As such it can be used in addition to (rather than 'in place of') other industry printing standards such as SWOP, or GRACoL.

Contents

From the IDEAlliance website

G7® specifies the components of an image that define a similar "visual appearance" to the human eye. To do this, the G7 Specification:

History

Initially G7 was developed by the IDEAlliance GRACoL Working Group. But as adoption of G7 grew, it became clear that the application of this specification that enables printers to reproduce a similar visual appearance across printing types and substrates should be addressed by a group with reach beyond the focus on sheetfed offset printing that is unique to the GRACoL working group. Today, through the PPC Working Group, experts from across the spectrum of printing disciplines contribute to this important IDEAlliance Specification.

How to get it

The G7 specification is managed by IDEAlliance. Documentation describing the process is freely available at the IDEAlliance website which describes the specification and how to achieve it.

A "How to" document is available here:
and an updated amendment for the "How to" is here:

[to G7 How to]

A list of downloadable G7 documents is here: [[1]]

IDEAlink Curve

IDEAlink Curve is software that greatly simplifies

Personal tools
Namespaces
Variants
Actions
Navigation
Toolbox