G7

[dadeo1717]

Can any on tell what you use to measure G7 standards and anything you know about G7?
We are thinking of trying to get G7 certified at our shop.

 

[TechnaPrint]

G7 is a printing standard that helps you keep your blacks neutral.
We have been using G7 for three years now and our customers love it. We are very consistent and our proofs match the presses 99% of the time. It really does make printing photos look better, however, we do have a little issue with light pastels and tan colors (they tend to be slightly lighter on the proof).

For more info, check out "http://idealliance.org/industry_resources/branding_media_and_color/g7"

As to what we do-
We hired someone to come and go through the G7 certification with us for the initial certification. We have been doing it ourselves for the last two year to re-certify. We use an Eye-One at the press to read custom color bars (from SpotOn!) that we have added to each press sheet to verify that we are running to the G7 spec on every job. To verify G7 compliance, we use a Xrite DTP-70 to read the press sheets in to the computer. Then we use ColorPort and Curve 2.0 to read and analyze the press sheets.

Hope this helps.

 

[gordo]

G7 is a printing standard that helps you keep your blacks neutral.

A small clarification - G7 is a method not a standard. The method defines a colormetric definition for gray balance rather than to keep blacks neutral.

best, gordo

 

[Bloodsaler]

Gracol and swop is the standard,but G7 is the method to carry out gray balance result~

 

[dadeo1717]

Thank for the info as we are considering going G7 in our shop. I was wondering what the pressmen think of this method and was it a big change in the way they print? Also don't you have to use a different denesitometer that measures L a b ?

 

[gordo]

Thank for the info as we are considering going G7 in our shop. I was wondering what the pressmen think of this method and was it a big change in the way they print? Also don't you have to use a different denesitometer that measures L a b ?

Most press operators don't care much about the methods that prepress uses. What you may decide to do is to determine the solid ink densities using a densitometer at the correct Lab values measured with a spectrophotometer. Once set up, the press operator can continue to use solid ink densities in day to day production while a spectrophotometer shared with prepress is used for color checks as needed or if problems arise.

best, gordo

 

[rich apollo]

Thank for the info as we are considering going G7 in our shop. I was wondering what the pressmen think of this method and was it a big change in the way they print? Also don't you have to use a different denesitometer that measures L a b ?

Shouldn't matter to the pressman at all. Match the proof, or don't match the proof - end of story.

You don't need any special devices other than during the calibration runs. The calibration takes you through the process of determining the density and TVI values that will bring you into compliance. You can pretty much monitor the press runs densitometrically - even gray balance.

If you decide to monitor compliance with something like SpotOn, pressSIGN, or PrintStandardizer; then you'll need a spectrophotometer.

 

[CKL]

G7

Techna print, 99% is a great number.
What do others see on average? job to job.

How many different curves are required?
How many different presses run off of the same curve?
How many different papers are certified?

Thanks

 

[David Milisock]

run length

run length

I was wondering how much value the standard has with the reduced run length these days

 

[gordo]

I was wondering how much value the standard has with the reduced run length these days

Why would run length make a difference?

gordo

 

[Colorblind]

I was wondering how much value the standard has with the reduced run length these days

It may not answer your question but from am advertiser/print buyer point of view, the latest Gracol 7 and SWOP 2006 color data / appearance which are obtained using the G7 method makes it a lot easier for us to predict color and produce our own proofs. For the sake of color consistency between different printing technologies, we always ask printers to match Gracol 7 color (or SWOP 2006 for web printed jobs) even on short runs and digitaly printed jobs.

 

[David Milisock]

run length

run length

Lets face it with run lengths of 300 to 500 impressions (which are very common in my area) I wonder how stable the water system gets inthose short runs? Sort of negates much of the work in other areas.

With digital work the instability of even certified papers can negate the value of non0stock profiles.

 

[TerryWyse]

Why would run length make a difference?

I was thinking the same thing! Whether you should print to a specification or not is up to you....but I don't see where run length would enter in to the picture. In fact, I would argue that if printing to a specification establishes metrics (like gray balance and colorimetry) that reduces make-ready, then all the better for short run jobs.

And not to get TOO terminology anal.....G7 is the *methodolgy*; GRACoL, SWOP, et al are the colorimetric aim points and/or specification....none of these are *standards* in the strictest sense.

terry

 

[David Milisock]

I was thinking the same thing! Whether you should print to a specification or not is up to you....but I don't see where run length would enter in to the picture. In fact, I would argue that if printing to a specification establishes metrics (like gray balance and colorimetry) that reduces make-ready, then all the better for short run jobs.

And not to get TOO terminology anal.....G7 is the *methodolgy*; GRACoL, SWOP, et al are the colorimetric aim points and/or specification....none of these are *standards* in the strictest sense.

terry

I agree the run length doe not negate the use of a specification but with short runs length on wet offset do they negate the use of anything that's not just factory?

lets acte it for a plate setter you have to set up the postscript color management just to be ablr to make a plate and it works well.

 

[Lukas Engqvist]

I been out of this, but I'm not sure I agree... I find that (wet) offset is much more stable than digital prints. Yes there is the make ready sheets, but with good Inking curves startup is down to much less sheets. Compared to a digital "press" you'll find variations depending on time of day and how long the print run is.

We printed posters down to run lengths of 50 in offset with the ink key setting presets. This does mean you have to trim your inking curves over time, and I know too many printers that "play piano" by feel on the control table rather than invest in a long term fine tuning of the CIP3 vs inking curves.

 

[TerryWyse]

I agree the run length doe not negate the use of a specification but with short runs length on wet offset do they negate the use of anything that's not just factory?

Hi David, I'm not sure I understand what you mean by "anything that's not just factory".

lets acte it for a plate setter you have to set up the postscript color management just to be ablr to make a plate and it works well.

Again not sure what you're trying to say.....and I'm not an advocate for Postscript color management in any case.

Terry

 

[David Milisock]

Hi David, I'm not sure I understand what you mean by "anything that's not just factory".




Again not sure what you're trying to say.....and I'm not an advocate for Postscript color management in any case.

Terry

Some hardware software configurations allow more sophisticated calibrations, for pres most if not all start wit h a postscript color management configuration but allow the technician to tweak the curve. In my experience I'm at a point where I can't justify the ROI for such a time consuming process.

As far as PS color management goes (now I admit the systems I work on range in the $100k costs) you have to use it to set up the plate setter PERIOD. Even if the setter allows the use of ICC profiles the final conversion will be to the pate curve so why bother with the ICC ate all. Just tell the designers to use a list of commercial ICC profiles when designing and use PS color management in the platting process.

Now I completely understand not using PS CM on digital print engines as any of the RIPs I've seen are all designer as ICC controlled only, but its' the opposite for plate setters. So what don't you like about PS CM?

 

[rich apollo]

Why would run length make a difference?

It depends on whether you use statistical process control, or not. Standard deviation is based on the number of attempts. As the run length gets longer (more attempts), the allowable variance (number of failures) grows.

If you use arbitrary numbers to establish the control limits, then run length doesn't really matter. Just gotta' be sure those numbers are based in/on some kind of reality.