ColorNews Issue #75

G7+ ... The Inside Skinny

  CHROMiX ColorNews
   Issue #75 - May 16th, 2024

This Month's Contents

  1. CHROMiX News
  2. Latest blog entries in ColoRants (and Raves)
  3. Shows and Events
  4. Color Industry News
  5. Forum Topics, Random Bits, etc.
  6. Article - G7+... The Inside skinny
  7. CHROMiX Open Box items for sale
  8. ColorNews Admin (feedback, subscriptions, etc.)

For the very freshest color updates, check out our blog Colorants (and raves).

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CHROMiX News What the heck have we been up to?

CHROMiX is 25 Years old!

How about that! Here's raising a virtual glass of health to our customers, families, friends and colleagues to celebrate.

CHROMiX is going to Drupa

There's more info below but we didn't want you to miss it.
We have a presentation in the Fogra booth (11-F71) Monday June 3rd at 2:00 pm

G7+ and Curve+ Announcement

Heard the recent news about G7+ ?
Here's the announcement:
PRINTING United Alliance Announces Groundbreaking New G7+?
That's G7 'PLUS'. And it is a big plus at that.

Curve+ is the new version of Curve that supports G7+ (in addition to G7, SCTV and TVI). We shipped Curve+ shortly following the TAGA/COLOR Conference in Dallas, TX in March. There's a bunch more Curve+ information below. In short, it: is a great upgrade to Curve4, fully supports G7+, continues to be the best G7 tool available, includes a new calculator tool for printing aims, has a bunch of new UI features including sorting control over files in the sidebar, dark mode, modifies existing ICC profiles, and numerous other additions.

At the conference, Don Hutcheson taught a pre-conference session titled: G7+ Expert Course and Certification. and Curve+ was available to all attendees to try G7+ for themselves.

More about the TAGA/COLOR Conference HERE

PLUS (no pun intended!) CHROMiX has an Article below about 'UNDERSTANDING THE NEW G7+'. Check it out!

ColorThink v4

Yes, we are nearing the release ColorThink v4 in the next couple of months. Promise. Many of the technologies we've developed for Curve and Maxwell have found their way into ColorThink and we know you're going to love them.

ColorThink is currently being vetted and tested and we'll let you know when it ships.

This long-anticipated update is a huge upgrade from Pro version 3 and the features we're showing include:

+ Many additions and improvements to the Grapher
+ New viewing spaces and modes
+ Image flow (must see)
+ Graph views (saveable perspectives / positions)
+ Gamut comparison/subtraction w/ GCI
+ N-channel graphing improvements (huge!)
+ dE blobs
+ New Color Assets handler
+ Integrated instrument support
+ Color Worksheet improvements
+ Color patch tuning
+ SCCA conversion
+ List joining and filtering
+ Gamut boundary selecting
+ Completely modernized interface

And much, much more

Steve Upton was at the recent TAGA/COLOR Conference presenting the session: Color Gamuts and Other Visualizations: An Update. ColorThink 4 was instrumental in clearly showing these advanced concepts in a clear and intuitive way.

CHROMiX will be showing ColorThink 4 at DRUPA Dusseldorf Germany on June 3rd in the Fogra booth. See Events below for full information.

NEW Website

CHROMiX has a brand-new website and store at!

This is a complete makeover with a more modern interface that makes navigation easier. It has all of the essential elements and more. Let us know what you think.

CHROMiX Sightings

See events below as we are attending all events listed.


CHROMiX Blog Here are some of the recent posts to our blog: Colorants (and raves)

Shows and Events Color-relevant gatherings to plan for

March 12th-14th, 2024 - Steve Upton hosted a session titled Color Gamuts and Other Visualizations: An Update.

Don Hutcheson taught a Pre-Conference Session for G7 Experts wanting to get G7+ certified. Don used the new Curve+ version while teaching.

The industry, by and large, seems very excited for G7+. With Printing United Alliance at the helm guiding this, we are excited too as Curve (now called Curve+) once again leads the way into this new and great color wilderness!

May 5th-8th, 2024 - Steve Upton was included in the session "ICC, Do You CC?" providing the section "The Mechanics and Details of ICC Profiles". In this session Steve provided insight into what is contained within ICC profiles and what do 3D plot of them actually show us?
Why look at profiles visually with a gamut viewer and analysis tool? (yes, he did use ColorThink v4 to show examples).

May 28th - June 8th, 2024 - The largest show for print in the world and it's been 8 years since the last event.

CHROMiX will be there to promote ColorThink 4 and meet partners, resellers and customers. If you are there and want to meet with us, reach out to Rick Hatmaker at hatmaker (at) CHROMiX (dot) com.

While at DRUPA, view the NEW ColorThink 4!

When: Monday June 3rd at 2:00 pm
Where: Hall 11, booth F71 (Fogra)

Topic: New features of ColorThink 4 and how Fogra uses it for color education. Steve Upton will present along with Fogra's Andreas Kraushaar.

Come join us!

September 10th - 13th, 2024 - The largest show for print in North America. And once again, CHROMiX will be there. More details to come.

Events Calendar: For all current and future events, bookmark this calendar.

Color Industry News What's going on in the world of color

Epson introduces a new Color Management system

Epson has announced a New Auto Chart Reader Accessory plus Epson Edge Color Lite Software to work with the Epson SD-10 Spectrophotometer to Provide a Full Color Managed Workflow. It is also advertised to work with Epson's new PORT cloud-based monitoring system. WTT had a great write-up here.
Our $.02 thoughts: It's slightly smaller than we might have imagined, but the price is right.

Epson announces PORT and EdgePrint

Epson announced and released their new cloud-based PORT and EdgePrint reporting software that now works with most new Epson printers to monitor usage, consumables, costs, maintenance and more. Nice to see something exciting like this from Epson. Most users should check this out, but especially production and enterprise users.

Barbieri announces New SpectroSwing qb

This is an all new version of and replaces the prior SpectroSwing model. The SpectroSwing qb is an automated sheet reader that features the same qb head as the LFPqb. Measures reflective and transparent media in M0, M1 and M2 modes. Featured in the CHROMiX ColorGear store.

Forum Topics and other bits  Popular topics from and other things we've found along the way.

mini DisplayPort with Apple Silicon:   Brian Lawler has taken his frustrations about mini DisplayPort compatibility with the new Apple Silicon systems and written a helpful article. A must read.

Spectral Data: The Language of Color:   Mark Levine writes an excellent short article explaining why spectral data is the heart of all color.

G7 Basics, again:   We posted this succinct overview video a while ago, but with the topic of G7+ now the buzz, we felt it's a good idea to refresh what G7 is to begin with. It's a simple, G7-basics-within-Curve4 video intended for people who have never used Curve software before, are thinking about G7, and just want a simple primer on how to do it. Pass this along to newbies or customers who you think may be G7 candidates.

G7+... The Inside skinny by Pat Herold

The New G7+ Specification

There's an old adage that says there's an exception to every rule. That might be true, but when you end up with a lot of exceptions, it would seem that the rule might need updating.

In previous newsletter articles on G7, we have proudly bragged of adding new features that enabled our Curve software to be better suited for various printing technologies. For example, we added the "normalize high densities" function" - and a button for using "Native CMY."

While G7 works very well, these are hints that more can be done to improve calibrations in certain areas, and some of these improvements require the software to step outside of the specifications for G7 as it currently exists. Exception checkboxes are not ideal. The best way to solve this was to improve the G7 Specification.


G7+ was announced in January and introduced to the world at the Printing United Technical conference in Dallas in March (2024). Much new information is coming out about this new specification and we will try to update this article in its online location with any new updates as they happen.

As we say around here,"Once you have the transmission open on the bench top, you might as well go in and fix everything." Those who are putting this together are making good use of the "opening up" of this spec so that much can happen to make printing better- without making the lives of printers worse.

Some things you DON'T have to worry about:

+ If you're happily printing to G7 now, the addition of G7+ is designed to not upset the applecart. At typical commercial offset ink levels, G7+ should closely resemble G7 appearance.

+ Images that were printed based on the GRACoL color space will work well in a G7+ workflow. And likewise, images based on a G7+ workflow will work fine in legacy GRACoL workflows without change.

Some of the benefits G7+ provides:

+ G7+ datasets can be SCCA-adjusted by an unlimited amount without affecting G7+ compliance, while even a small SCCA change can damage a G7 dataset's gray balance.

+ G7+ takes care of an issue where high-density printers would sometimes see banding in gradients (think deep blue sky images.)

+ The new G7+ algorithm improves the gray balance even on strongly colored substrates.

In more depth:

Gray Balance

With G7, the gray balance process works best if the 300% CMY is exactly 0.0 a* b* (perfectly neutral). If your media and 300% CMY overprint are fairly neutral, this works fine. Many people don't notice what color "black" is anyway. But picture a strongly-colored substrate with low contrast: a yellowish newsprint. The color of the substrate will still show through all the gradients in the shadows toward black. A warm gray balance heading toward a neutral black will be jarring to the eye. The shadows would end up looking blue to the naked eye using G7 only.

G7+ adds a portion of the substrate color back into the calculation of the 300% aim point. The result is a natural-looking gradient all the way from warm highlights to warm shadows, for instance. G7+ will do the same color adjustment with any strongly-colored substrate - like fabrics, colored papers, and plastics. One way to think about it is that G7+ works like the Relative Colorimetric rendering intent.


Packaging printers and commercial printers are commonly trying to print to GRACoL but often have to alter the GRACoL profile to reflect the paper white of the different media they are printing upon. This is a perfect opportunity to use SCCA (Substrate-Corrected Colorimetric Aims). In actual practice, when making even a small change to the substrate color, the G7-derived gray balance of GRACoL is messed up by SCCA. Gray balance produced by G7+ survives the SCCA process intact.

G7+ has been altered to use a similar algorithm to SCCA, so that color modified by SCCA will perfectly maintain the G7+ gray balance.

High Density Smoothing

This is the kind of feature that drives people in the marketing department nuts. High Density Smoothing (HDS) is the feature that does not show up in the user interface!

Curve4 has a checkbox so the user can enable the ability to "Normalize High Densities". The checkbox comes with a foreboding warning that using this feature could "cause shadow tonality to fall outside of the G7" specifications. At the same time, some people printing high density inkjet work found that applying the G7 solution to these dark shadow areas was wreaking havoc. The G7 algorithm recommends changes that do not make sense in some cases.

What to do?

Change the specification!

In layman's terms this new method makes use of the G7 method of CMY grayscale correction from paper white up to the 75% cyan ink level. Above that, CMY tonality is based on TVI curves taken from GRACoL 2013 (CRPC6). This Reference Print Condition has nice smooth curves going all the way up to full density, and it manages to tame the beast of high densities nicely. Naturally, there is advanced smoothing and other fancy math done to make the transition smooth.

It's also part of the reason why, if you're already printing to GRACoL 2013, that G7+ calibrations will not change things much at all.

With Curve+ there isn't a checkbox for "Normalize High Densities" because it's all done automatically. G7+ with HDS will allow smoother transitions in strongly colored gradients, and even flesh tones will have slightly improved contrast - a particular benefit to those in wide-gamut inkjet printing.

New Targets

Compared to a manual transmission, that automatic tranny on your bench involves more work to rebuild. In the same way, all this G7+ automatic goodness has added some new requirements, though they're not too taxing.

In order to pass the G7+ spec more patch colors need to be measured than before.


Before, to pass G7 grayscale, you needed to measure at a minimum, the G7 Verifier 54 patch target. With G7+ the minimal patches required are found in a new 84-patch G7+ Verifier target that adds the necessary CMY high density ramps.


When calibrating, there is also a new "P2P" target that is available for use. The P2P75+ target is like the P2P51 that most of us have been using. The difference is that it is optimized for G7+ by adding 75% and 85% patches of C, M and Y and removing the 95% R, G and B patches. The P2P75+ has the same number of patches as the P2P51 and takes up the same space on your press sheet, so it's another thing you don't have to worry about.

Note that with the Curve+ implementation of G7+, you will be able to continue to calibrate with the P2P51 target when needed. Curve+ will automatically interpolate the 75% C, M and Y patches using neighboring patches. And then of course when you are using the P2P75+ target, Curve+ will happily make use of those patches when it finds them.

Universal Characterization Dataset (UCD)

A final point to keep in mind is that G7+ is positioned to be easily adopted as an international standard. The industry expects this to be happening sometime in 2024. Whether or not your shop considers itself an "international printer", the more this specification gets adopted, the more it will be known, and the more people will be asking for it in the future.


So far, this article has mainly been focused on the G7+ specification. CHROMiX has been an ardent supporter of G7 in our literature and products from the very beginning. In keeping up with industry advancements, CHROMiX has released Curve+.

Curve+ fully implements this new G7+ specification with the easy and intelligent software design you have come to know from our previous products. Curve+ is backward-compatible with Curve4 files, and will easily open Curve4 documents to allow saving them out using G7 or G7+ methods.

In a number of ways, you can think of Curve+ as being Curve5, but now we've settled on a name that doesn't change which each major release!

To be clear, G7 is still fully supported in Curve+ and will be for the foreseeable future. The language in the original Printing United Alliance announcement suggested that G7+ was intended to replace G7 in the near future. In reality, G7 is expected to have a comfortable grand-fathering period (after all, there are tons of facilities and equipment G7 certifications that won't expire for up to 2 years). We expect to support G7 in Curve+ throughout that period and probably a lot further into the future. We're happy to support what people want to use. That said, we're confident that the changes in G7+ are great improvements and in attention to keeping G7's "sweet spot" unaltered, will make the transition from G7 to G7+ smooth and very much worthwhile.

A great deal of effort has been put into making this adoption as minimally disruptive as possible. We'll have that transmission back in your car and have you on the road to printing success in no time! Be sure to contact us at CHROMiX or in our with any questions that you have.

Thanks for reading,

Patrick Herold

To read this article with images in ColorWiki, click here

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