Adjusting Curves to changes in materials

[Prepper]

We have been using the G7 method for 4 years now with good success, when the curves are new and things are stable.

Biggest challenge we have is keeping stability at press due to changes in materials, papers, inks, etc. How do you all deal with that on an on-going basis? Are you constantly re-printing targets to make new curves? We only have one press and have this problem, can't imagine dealing with it on 4 or 5 presses or more. It seems like every time we settle on a paper and\or ink combination, it's not long before there's some issue of one kind or another with the paper (usually) and we switch to something else, so curves may or may not work the same on the new paper, so color match to the proof may be off a little.

Is there software at press side that will continually update your curves accordingly for the G7 spec as press conditions\materials change?
Something in scanner software or closed-loop system?

Thanks

 

[lynnic]

We are also G7. We found we needed to set curves for each press (we have 2) and for each of the 4 common stocks we print on.
If there is software I am interested to know as well. We do reuse the CIP files from run to run which I believe holds that information.
Good Luck

 

[Astro]

Is there software at press side that will continually update your curves accordingly for the G7 spec as press conditions\materials change?
Something in scanner software or closed-loop system?

Thanks

Hi Prepper, a software solution called Alwan Print Standardizer, might be what you are looking for. APS can manage and update your press curves to maintain G7 automatically or semi-automatically (depending on your workflow), even when your press conditions change. The software has the ability to connect to press side scanning devices like X-Rite Intellitrax and read your colour bar (as long as it has all primary solids and at least 3 tints of each) and use that data to build a new curve. It is an iterative process so it will update your current curve to the new printing conditions. The advantage is that you don't have to dedicate a press run to re-print targets every time something changes.

Full disclosure: My company is a reseller of this product but I am a G7 Expert have installed this software at several printers with great success. If you would like more info, feel free to PM me.

Thanks,

 

[chevalier]

Ideally each stock should have it's own curve profile per press created via G7 if you are holding and verifying your press sheets to GRACoL, SWOP, or FOGRA. Note that many stocks aren't going to achieve these results due to a different paperwhite LAB value. This isn't realistic or economical unless your customers are paying for extreme accuracy. Most shops tend to have a profile curve per press for coated and uncoated.

 

[rich apollo]

Is there software at press side that will continually update your curves accordingly for the G7 spec as press conditions\materials change?

Absolutely!! You've hit on the toughest bit of G7 calibration - things change. Fortunately, there are several software solutions to compensate. Alwan Print Standardizer was mentioned. Bodoni Systems' PressSign, Alder Technologies' Spot-On!, Heidelberg PrintOpen... Help is out there. Also, most, if not all, of these groups will grant you a demo license so you can get a feel for how they operate.

PM me if you want/need contact info for any of these.

 

[Kaoticor]

We currently use a program of that general nature, MPX (My Press Xpert). It uploads our scan data real time, provides data analysis, remembers previous curve adjustments you have made with it, and calculates a new calibration curve automatically. We do apply the curves manually though in the program we use (Harmony) after exporting the data as a Harmony Curve file. It seems to work well, I just have to take 15 minutes every couple of months or so and apply the new correction. The algorythms for the curves seem to have come a long way in my opinion.

Now that our press is up to standard, we use this program to maintain our color through the difference in materials and it seems to work well for us personally.