1. What is the difference between GRACoL, GRACoL7, and G7?
GRACoL is a set of specifications for commercial printing developed by the GRACoL committee, a member of IDEAlliance
GRACoL7 is the latest version of these guidelines
And G7 is the methodology used to meet these specifications
2. What is a traditional press standard based on?
SID (Solid Ink Density)
TVI (Tone Value Increase or Dot Gain)
Wet ink trap
6. Why is it better to use colorimetry than density?
Because colorimetry considers color and color balance rather than the weight of ink on paper
And because it gives the ability to define the appearance of color and to monitor color change
7. What is a Neutral Print Density Curve (NPDC)?
NPDC is a target curve defined along the entire tonal range. GRACoL7 defines a specific NPDC curve that allows the press to run to its natural tendencies, using plate compensation curves to correct for unwanted behavior.
It uses the entire tonal range not just the traditional TVI 25%, 50%, and 75% values, giving you the entire shape of a curve, from highlight to shadow
8. How is Highlight Range (HR) used for process control?
As a quick check to visually compare a 50/40/40 CMY patch to a 50K patch
As an additional checkpoint, to check gray balance in the 50/40/40 CMY patch
And to monitor the TVI of the press run
9. What are the benefits of the G7 method? They are:
Faster make-readies because the press operator can quickly determine the ink balance on the sheet using neutral and black patches
Better control on press because G7 uses colorimetry
Gray-balanced plate curves improves the press’ ability to print neutral through the whole tonal range
10. Am I a good candidate to switch to G7?
Yes, if your color make-ready is taking longer than you’d like
And if you want to spend less time measuring press sheets
Also if your customers complain about the quality and the consistency of your color
Or if you need to match color appearance across multiple presses or press types.
G7’s success was so spectacular for GRACoL workflows, that G7 methods were tested on other workflows such as SWOP. Managing gray so carefully paid dividends in SWOP workflows and in other workflows as they were tested. Today, a series of printing conditions has been defined in a new standard, CGATS 21-2 (ISO PAS 15339). This family of print conditions, referred to as the CRPC1-7, has seven categories, each with its own reference data set. All of them share a visual appearance because they’re all based on G7 neutral gray appearance.
These seven sets are called:
ISO15339-CRPC1 - Typical ColdsetNews – Small gamut printing (newsprint)
ISO15339-CRPC2 - Typical HeatsetNews Moderate gamut printing on improved newsprint type paper
ISO15339-CRPC3 - Typical PremUncoated Utility printing on a matte, uncoated type paper
ISO15339-CRPC4 - Typical SuperCal General printing on super-calendared paper
ISO15339-CRPC6 - Typical PremCoated Large gamut (typically commercial) printing
ISO15339-CRPC7 - Typical Extra Large Extra-large gamut printing processes
Alain De Borger seeks out the most innocuous scene and makes it into a glorified landscape. People become beautiful in his pictures. He lives his work. “Since the beginning with Agfa IsoRapid and its development curve, to today, my work is varied. In spite of many detours, it remains close to the documentary or, vital to me, a connection to reality.” We are proud to display his work.