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Offline motormount

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konica c6085 color and igen4 digital printing issues.
« on: March 08, 2020, 01:59:21 PM »
 The last 10 months i'm running the production in a middle sized plant, a 5 color KBA, bindery for saddlestiched jobs, two konica's c6085 and an igen4 digital presses ( and a couple of other's post press finishing machines ).
 
 
 I'm facing a lot of problems with the digital printing ''presses''.


 Till now my experience with digital printing was a bizhub 7000, when it was working, which when it worked it rarely printed good, and two label printing indigo's ( excellent machines ).

The excuse the tech's tried to use for the printing quality of the bizhub was the printing room temperature, humidity and dust collection. 

Unfortunately for them, all of the above were not an excuse since the printing room was the same with the ctp, and it was clean with steady temperature and humidity conditions.

No solution was found, till i left the shop and went to the label manufacturer with the indigo's.

Now i'm facing the same problems with the c6085's and the igen (4).

The ''presses'' break down all the time, i'm sure that they are down more hours the day than the hours they print.

But unfortunately for me now, i don't control the conditions of the printing room the digital presses are in, and the tech's put the blame on the dust and temperature/humidity factors ( which are not stable and for the near future the owner can't and won't do anything about it...)


Apart from all the hours the machines are down, i have a serious problem with color reproduction.

If i print the same file on the 3 machines, i'll get 3 different products ( color speaking ).
- Maybe more come to think of it in some cases, as color may shift during the run -

I don't want to color manage anything.

I want the machines to read only the CMYK values of the files, and reproduce them according to the FOGRA39 standard.

To achieve this, techs told us that we should use the ''bypass conversion'' adjustment on job color settings, but then color comes out with a shitty yellowish hue all over the sheet.
So we use the built in color manage profiles and eyeball the print in comparison to our cheap secretary screens before we run the job... 
- thats on the two konica's-

 :banghead: :banghead: :banghead:

The igen can't print on plain stocks below 100gr and we never know beforehand if a 100gr or 120gr plain stock will be printed so we test it first and then cut the paper to it's final size...

Even then, if it is a big run it might start well and after 200-500 sheets the press won't process the stock - sometimes -  :banghead: :banghead: :banghead: :banghead:

Color is not stable either, even though every morning we run the calibrating procedure....

Two questions:

A) What do you think about the color reproduction of the konica's?
Does anyone here print's on these machines and how you handle color reproduction?

B) What stocks your igen4 won't handle well ( or at all ) ?

ps I left the best part last.

There's no actual proofer on the shop.

Clients sign the digital prints, and then the offset guys try to mach them on the KBA - if it's an offset oriented job -

 :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead:

« Last Edit: March 08, 2020, 02:03:00 PM by motormount »

Offline jwheeler

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Re: konica c6085 color and igen4 digital printing issues.
« Reply #1 on: March 10, 2020, 02:23:08 PM »
We have a C6085 here...we don't have a 2nd one that we try to match color on so not something we face. However, matching colors between any 2 digital presses from any manufacturer is always a challenge, especially if you're not willing to do color management. In an ideal world, you can go through the G7 process to make all of your digital and offset presses match...however, this is costly and requires extensive training. To make things easier, you should calibrate your digital presses daily (or at least weekly) using a Spectrophotometer. I used to be in a shop that had a C6085 and C3070 and we were able to get them to match very closely just doing that.

If you have Fiery's on all of the units, you can get Fiery's Color Profiler Suite software (I know you don't want to profile, but it's what you have to do) and share a profile between the presses. A Fiery Specialist or your Xerox/KM specialists can show you how to use the software once it's installed. Additionally, do you know if they have the IQ-501 on the C6085's? If you use the built-in auto color management of that unit, it will help maintain it for you automatically.

Lastly, you mention all 3 digital presses are having issues printing. Temp and humidity are definitely a big issue for digital presses. Additionally, if they happen to be in the same room as your offset press (or sharing the same circulating air), the fumes from the chemicals used to clean the press are very problematic. So much so that when I used to sell digital production presses, we had a waiver for the customer to sign acknowledging that the VOC's will cause issues on digital presses.

Offline DigiCorn

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Re: konica c6085 color and igen4 digital printing issues.
« Reply #2 on: March 10, 2020, 02:42:33 PM »
At THIS shop we run a Xerox ColorPress 1000i and based on getting bitten multiple times in the past, we have taken to proofing the job on the ColorPress on actual stock (if available) as imposed... for press work (we have a few 2-color Ryobi presses (with a common blanket)), we run it to our little Sharp color copier and then attach a Pantone chip and make the customer aware that we will run to match the Pantone book (or previously printed sample). We also have no proper proofer, but then again about 75% of the work in this shop is digital and about 85-90% of work in the other shop is digital. If we need 4-color press work, we send it out and make the vendor responsible.
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Offline motormount

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Re: konica c6085 color and igen4 digital printing issues.
« Reply #3 on: March 15, 2020, 10:42:35 AM »
There is a spectro in the shop, and we calibrate the presses daily.

But that's calibration, not color management i suppose.

So after calibrating if you print the same file on both presses, sometimes match, others may be a little bit different, and sometimes may not be close to each other at all...

But the biggest problem is that even if the prints match between the presses, we are not sure about the colour accuracy.
 We tell the press to bypass the profile of the pdf ( when there are any ) and respect the CMYK values only.
And there is a yellowish hue on the print.

We can't use the spectro to calculate the color shift, it's dedicated to the press and we can only measure a build in press chart for the daily calibraton.
- we don't actually have access to the spectro readings, we print the chart in the morning, read it and the press updates it's profile -

That's as far as it concerns the two konicas.

With the igen - when it comes to color - things are a little bit better.

We also run every morning a color check routine, the prints are closer to a fogra color chart, but we can't check the accuracy either, sometimes the shadows are blocked, other times color shifts during the press run...

Like i said the conditions of the pressroom are not the best, there is a lot of dust, even though we try to keep it as clean as possible, and humidity/temperature cannot be steady.
 -The plant is 6 meters tall, with 3 meter wood ''walls'' to separate deparments,bindery, offset, digital and management/sales offices -

As i wrote, management won't take any measures in the near future - apart from cutting down personnel... -
But i'm not really sure either that if the conditions were excellent the presses would operate right .
( judging from the one i used in a clean, closed, air conditioned  room a couple of years ago )

 The client hard copy approval is rare an option, as we run 10 to 20 different jobs a day, many of them delivered same day or a couple of days later.

Maybe now we slowed down ( almost stopped ) because of the virus crisis, we'll find the time to deal with it.


Offline AaronH

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Re: konica c6085 color and igen4 digital printing issues.
« Reply #4 on: March 16, 2020, 10:49:05 AM »
Is it possible your calibration/color management is set to have a paper simulation of some sort? I know this is a little different, but when setting up our Epsons to be driven through XMF in the color management/DLP creation software we have the option to turn on paper simulation or turn it off. Basically this makes White, yellowish if it is on and affects every other color when measured. We keep it off. I'm not sure on our Xerox, we have a Fiery rip on our Versant 80 and I don't remember if it had that as an option.

For color management to try to get your presses to look similar is it possible to point them at a GRACol or Fogra icc profile? Then create a device link profile for each digital press that points to that icc profile? I'm not familiar with Konica's or ink driven Xeroxes (if the iGen is ink).
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Offline motormount

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Re: konica c6085 color and igen4 digital printing issues.
« Reply #5 on: March 20, 2020, 04:14:15 AM »
Not really sure, but the way i see it is not paper simulation problem - or i don't see ''that'' button-.

Our konica presses are supposed to point the fogra standard, and sometimes they actually achieve that, eyeballing the prints next to my colorbook.

To be honest, i think that all of this presses are extremely sensitive to humidity and temperature changes, but even if you provide them, they still have problems on multiple issues, paper handling, color etc.

So, i'd like to hear if anyone works in a shop with steady - and proper - humidity and temperature, is printing without any major issues ( color, paper etc ) with these models, or that they suck wherever you put them ( as i believe, but can't tell the techs now the way our printing room is ).