Tracking Profiles

[QualityPrint]

Hi All,
I am looking for ideas for a way to efficiently track the performance of your profiles. We use pdc-s scanning software to scan our press sheets but it is rather obnoxious to extract the information after the fact. Currently, we have the pressman write down on a tracking label the densities ran, the lab value of the gray (we use the G7 methodology), the lab value of the paper, and have them rate the match from press to proof. I would like to develop a more efficient method with no additional cost. (I have looked into other softwares like SpotOn but want to avoid added cost.) Please let me know how other companies are tracking the performance of their profiles and what data they (or you) are using.
thanks
Jeremy

 

[mglouis]

We're not talking about pdc-sII, right? In which case read on.

After you establish a G7 calibration that provides a reasonable match to your proofs consider noting your TVI for 25,50,75 patches as they relate to your house densities. (Ex: I know when I print 1.70 100K and if TVI for 50K is right around 20, then the NPDC for that patch is 0.50) It is easy in PDC-S to print a "single sample attribute report" for solid density and dot gain. This will be four reports. Staple them to the ok sheet from which the report was made. The reports should targeted and actual data for every patch across the width of the sheet - NICE! This leaves you without the LAB values for paper and for HR-CMY.

Rather than jot down the CIElab for HR we have a visual patch with adjacent NPDC K & CMY patches. As long as they match visually then your gray balance should be good enough for production, especially is you normalize your separations with a fair amount of GCR. Ex: 53k and HR-CMY [50c40m40y] should be the same darkness and have a very similar hue.

How on earth are you getting the paper color from a pdc-s? As far as I know, only if you have the latest build of version 3, can you get the spectral data for the paper patch in the form of a .SVF file. Side note: Pdc-s version 3 also provides deltaE ab* as an option. All previous builds report dE cmc.

Speaking of SVF, if you decide to spend some money and if you have the last pdc-s build, then take a look at Alwan Print Verifier. It reads SVF and gives you a TON of information such as TVI charts, lab values for every patch in your control strip, ab* plots for HR-CMY, paper color and gamut hexagons. Unfortunately the reports lack NPDC reporting. All your press operators would need to do is save copies of SVFs for your review and this can even be automated with a .bat. I am big a fan of SpotOn for various uses, especially as a press-side buddy for non-scanning consoles, but at this point in time it does not read SVF.

If you set up your curves under aqueous and use aqueous for production then don't forget to coat your color bars or else your control strip data won't be in agreement with your jobs. G7 is all about matching the visual appearance of grayscale's between printing systems so this step is key IMHO. Also it is nice to be able to scan an old gloss sheet knowing that dry back isn't a factor.

Kudos to your press to proof rating system. I would like to hear more about it. Is it an FYI system or is the feedback used to improve future matches?

Matt Louis

 

[Stephen Marsh]

Jeremy, what workflow do you use? For example, Kodak Prinergy has the Kodak ColorFlow component - which can generate very powerful and useful reports of a single condition or comparing a condition to a reference.

A free tool which you may wish to explore can be found here:

http://printplanet.com/forums/color-management/25998-valiproof


Hope this helps,

Stephen Marsh

 

[QualityPrint]

Yes we are using the PDC-SII scanning system.... We use a custom made workflow that does not currently support any tracking system. I know PDC-SII pretty well but there may be something useful within it to help me out that I(we) don't know about. Spot-On was the best software that we have used so far and we may go that route if it is our only option. What parameters do you all feel are necessary to track? i.e. dot gain, Lab values etc...

 

[mglouis]

To the best of my knowledge at this point in time there is no SVF support in SpotOn so getting measurements into it can be a bit of a chore. This is rumored to change in V2. I once made a 40" colorbar that contained three i-1 scannable strips which worked with an Excel macro to massage data for SpotOn ingestion so I had one color bar that worked with two applications. It was a lot of work and I could not keep up with all production sheets and have time for anything else. Most people add the SpotOn strip on a blank area of the sheet. Having the data in SpotOn was awesome for me but of less interest the press crews.

Alwan Print Standardizer and Print Verifier and Fuji Taskero will work directly with PDC-SII . Verifier is competitively priced to SpotOn. Check it out if you want to use measurements made from pull sheets.

Maybe it's just me but I find the closer I look at press data the more depressed I get. I am educated in ISO12647-2 and G7 and I have seen a greater disconnect with ideology and actual performance than I care to admit. SID trend lines can be stable while TVI dribbles like a basketball. I focus mainly on:
•*across sheet evenness (or range)
•*SID delta to target
•*mid-tone TVI delta to target
•*HR-K, SC-K & HR-CMY delta to target. (If I had to pick one it would be the 75K patch.)
•*gray balance

Since SID targets are established via dE correlation to a proofing specification our operators are concerned with keeping all the keys "in the green" in PDC-SII SID charts. Tolerances are based on capabilities rather than ideology. Older presses have looser tolerances. I check for sheet evenness (or range) very often and tell the plant manager when I see what looks like carelessness.

If an operator has to make a + 0.05 density move to match a proof acceptably then the operator is expected to report it to his manager and that info comes to me.

Operators know that on gloss paper that 50% TVI is in the mid teens for CMY and 20% for K. On uncoated those numbers are slightly higher. They are expected to say something to their boss if something weird happens (e.g. 6% TVI). If they do not and I find it myself then they are confronted by their boss. (I am the friendly rat who speaks to press operators through the pressroom manager. This way operators have only one person to answer to and the department head stays in the know.)

We track color errors, which is only one of many types of possible press operator errors. All operators get monthly reports on their performance. The goal is three maximum errors per month.

Gray balance moves like the wind but it only moves so far on a healthy day. If I can see it on the visual QC target then I dig deeper. I always take a gander at these targets when walking through the shop.

Odds are you won't use SpotOn or anything else as often as your operators make prints so putting processes in place on the shop floor may be the key to avoiding ugly trend lines the day after a bad day of printing.

For every job that has a color complaint for key patches I record in Excel the reference color, the printed color and the proof color. The XLS calculates dE for press to ref, proof to ref, and press to proof. Over time it has helped me understand what we can expect of ourselves and where clients draw the line of acceptability. Example: Our traps are too saturated on average but the hue is correct. Examples 2: Gray balance in the live job area is always very good (less so on the color bar).

If more people chimed in on this thread I think you would get a variety of answers. We track less than maybe we should but when data collection is not automatic you have to be choosy.
We also use Print Standardizer but this is just an fyi since it is beyond your budget - $10k. It is handy for browsing TVI, dE and d-Den for pull sheets without having to go into the PDC-S environment.

You might consider using the G7 Report that comes with PDC-SII Report Tool. Inform your operators to turn off keys that have negligible take-off and to mark production sheets or else your reports will contain data that should be filtered out in my opinion. You can key in what is important to you into Excel and chart anything you want. There's a handy spreadsheet made by Steve Suffolette of R.I.T. that trends SID, TVI & NPDC vs. time. Give me your email and I'll send you my modified copy of it which subtracts CTP curves to display both press TVI and print TVI, plots shift changes and outside temperature. Please keep Steve's name on the info worksheet so credit is given where it is due. There is a field for "modified by" where you can put your name. This is a thorough solution for trending data and prevents you from having to remeasure sheets or pay for additional software.

Occasionally I will rank the press operators by standard deviation and SID "keys out". This is an important step in getting them motivated to turn off irrelevant keys. Also if they do not go into production mode the report will err upon generation so they are also get a participation score (# of dataless jobs as a percent of all jobs). I make the reports whenever I think they think they aren't being actively managed.

-Matt Louis