What do next AM or Staccato

[herbert]

Hi all

Ok let me paint a picture.....

Im the PrePress Manager ( I have never operated a press !!!)
3 Heidelberg Press (2 x 102 1 x XL105)
No Print Manager only Print Team Leaders which work on different shifts..so no one taking full responsibility for the the Presses, because the Team Leaders are actually on press printing Jobs.
We use ISO12647 Target curves for Coated (FM20) and Uncoated (FM25)
We use image control to set the correct LAB Values and achieve these consistently (so no problem there)
We proof to Fogra39 via epson

I want to Move back to 200 screen for Coated and 150 screen for uncoated. Why...because to achieve ISO12647 dotgains consistently, FM screening is not the way Forward, what I have found any change on press can totally throw any calibrations ive done and this can cause us not been able to achieve consistent dotgain. (Hence we are always running print trials to correct this).

If we had a print manager to monitor the presses and a daily basis to check the following:
Blankets, Press Chemical, Ink, sequence, Press chemical etc to make sure these conditions are the same to when I calibrated, then maybe we stand a fighting chance of been consistent.

From my experience AM screening is more stable than FM Screening.is this correct ?
We need to achieve ISO certification the end of the year..im been told staccato is not included in the ISO certification.

Hope im making this all clear as Mud !!!

Any feed back would be great.

PS: Who can tell between FM and AM anyway....we dont print high quality work
Products - Greeting Cards, Commercial print and packaging

 

[ericmadsen]

My customers and prospects are aware of the difference and prefer FM. I've also found it more stable on press, which is to say that when I ask my operators to adjust the color, I see less dramatic changes in the print as ink density changes than I see with AM. I run FM20 even on a press with an outdated (contraindicated by Kodak) dampening system, and get consistent and smooth results every time. I'd recommend the FM for your consistency goals. Better, I haven't found a customer yet who prefers AM.

Make charts for your pressmen and plate makers and have them write down every variable they can measure. Process control is king, and this won't be any different in AM. If the press environment is all over the place, AM will give your operators more flexibility to take control of the color, but to base your product's consistency on their aesthetic judgements is to forego standardization altogether. Get your processes under control, write everything down so you can troubleshoot a changing processor and press environment, and keep color control where it belongs in a calibrated workflow: in prepress.

 

[gordo]

[SNIP]
From my experience AM screening is more stable than FM Screening.is this correct ?
We need to achieve ISO certification the end of the year..im been told staccato is not included in the ISO certification.
[SNIP]
PS: Who can tell between FM and AM anyway....we dont print high quality work
Products - Greeting Cards, Commercial print and packaging

If the press condition is correct - then FM screening is more stable on press than AM/XM screening whent solid ink densities vary. In terms of color, FM has a stability similar to "heavy" GCR separations. This has been demonstrated and proven many times by independent organizations like PIRA, GATF, and RIT.

FM screening displays a larger midtone gamut than either 150 or 200 lpi AM/XM screening. As a result, single and two color screen tint builds will not show the same color. This will make the presswork not quite align with AM screening based color specifications.

I don't understand what you mean by "we dont print high quality work" - your customers are paying you good money for your services and I think they may like having there jobs treated with respect.

In North America about 80% of all the Yellow Pages telephone directories are printed with FM. About 60-75% of all newspaper advertisting inserts are also printed with FM.
The two largest greeting card publishers - Hallmark and American Greeting - print their cards using 10 micron FM screening.

Some of the reasons printers use FM screening are described here: Quality In Print: FM/Stochastic Screening - Part 1 of 5 - The benefits

best, gordon p

 

[herbert]

Thanks for the replies.

Eric Madsen......Ok I take your point, but I guess the issue is, who have i got to make sure the processes kept up to...no print Manager....surely you cant expect a dreaded Prepress guy to tell pressmen what to do ?....I just think if we print AM, we dont have to keep tabs as much on processes..

Gordo
ok I take your point, but how do I proof to ISO standards if the midtone (pastels are not matching the proofs).I have had numberous occasions the 2 colour builds look at lot cleaner on press compared to proof....special profile for staccato?....but does this take us away from ISO ?

 

[ericmadsen]

It seems to me that management will care about process control - however you screen - if they're pursuing ISO. Logging press variables, even just once per shift, should be a part of every pressman's job. Point out that your present dependence on press operators' experience and judgement calls costs you time and money, and prevents your team from learning what's causing your press environment to change so much. Of course, you're already doing your part by logging your processor variables daily. If you weren't doing that, you might have a pretty consistent press environment and still see color inconsistency. Show management your log and see if they can meet with your best press guys with the goal of developing a chart to track variables so you can figure out what you're doing wrong. Because staccato is helping -- not hindering -- your consistency.

Calibrate your press, then calibrate your proofer to your press. Kodak can do the proofer calibration for you pretty cheap once you've run their form using plates calibrated to make your press print the curves you've chosen under your (written down!) press conditions. Your proof color will be a dead match for your press color when you're running to your density standards (write these down too!).

 

[gordo]

Gordo
ok I take your point, but how do I proof to ISO standards if the midtone (pastels are not matching the proofs).I have had numberous occasions the 2 colour builds look at lot cleaner on press compared to proof....special profile for staccato?....but does this take us away from ISO ?

ISO is a bit unclear about this. They state that the ISO specification is "applicable by analogy to line screens and non-periodic [FM] screens. However that's all they say. Technically if you exceed 80 lpcm which most commercially FM screens will - then you are outside of ISO from an image reproduction fidelity point of view. As far as color is concerned, I do not believe ISO specifies the color of screen tones. So you wouldn't be out of ISO color specification with FM. But the color will be different than the color of a halftone done at 60-80 lpcm.
Complicated isn't it.
If your customers supply you with ISO certified proofs and you print to their proofs or your own ISO certified proofs - then the FM will not quite match in screen tint areas from about 20%-70% in one and two color builds.
If you print to your own proofs then you could calibrate your proofer to your press and you will match your proofs and you can enjoy the other benefits of FM screening.
Some printers feel that it's more important to do the best job possible for their customers. Sometimes that means having more than one printing standard in the shop. One where you print like everybody else (ISO) and the other where you print better than everybody else (e.g. FM).

best, gordon p

 

[Prepper]

FM vs AM

FM vs AM

Gordo,

Never tried FM yet, we do 175lpi AM and use heavy GCR with good results. Is using heavy GCR with FM possible? You all are saying FM is more stable on press than AM but everyone has told me that press setup is much touchier for FM, is that true?

I'm wanting to try it but need to convince others first.

Thanks

 

[ericmadsen]

See what your ink vendors think about staccatto with your ink set... they may have advice. Also make sure your plates hold 1-99%. Also you can't print staccatto without correcting your plate curves based on a test print on your press to get the dot gain you want.

We get more consistent results than we did with AM, even when we'd just started out in FM and were using the same curves on radically different presses - including one that Kodak didn't expect to work well. I've seen terrible FM out of other shops; it can get really nasty like an antique inkjet if it's done way wrong, but in four years of running it we've never had this issue. Maybe it's to do with the software version?

I can't speak to GCR but don't see why it wouldn't work well. In my experience, FM is easy and better. The only things we usually use AM for are metallics and envelopes... the changing thickness of the envelope shows up as color variations in any FM screens printed over these areas. AM, less so.

 

[CD102]

I have some questions. My former plant ran a handful of staccato or stochastic trials. For whatever reason, we didn't embrace this technology. I know that staccato sees a smaller color shift when densities are run heavy, but what is the result when the densities are light? What are the results if you have doubling or slurring problems in a press? Would those problems have a lessened effect?

We had one press that needed a gear alignment and a gripper job before we shut down. To combat the problems the press had with doubling and slurring, prepress used different curves for the back rows for the magenta and yellow plates. Without those adjustments, the front and back rows wouldn't even look like the same item. I'm just curious if Staccato would have helped.

 

[gordo]

ericmadsen is giving good advice.

Gordo,

Never tried FM yet, we do 175lpi AM and use heavy GCR with good results. Is using heavy GCR with FM possible? You all are saying FM is more stable on press than AM but everyone has told me that press setup is much touchier for FM, is that true?

I'm wanting to try it but need to convince others first.

Thanks

You can use heavy GCR with FM.
To be successful you need to have proper process control in your print shop. If you can print 175 lpi consistently and reliably then you can print FM. If you are using your press to do color correction then you'll probably have trouble with FM. I mentioned the fact that 80% of Yellow pages phone directories in the US are printing with FM - these are not the most up to date presses.

This is a manual Planeta press from about 1949:

It prints cereal boxes using FM screening. Is your press as good as this one - or better?

Talk to your ink vendor and fountain solution people as they may have suggestions or recommend a different ink series for you (because the dots are smaller than what you're now using).

best, gordon p

 

[Prepper]

FM vs AM, heavy gcr and G7?

FM vs AM, heavy gcr and G7?

Gordo, forgot to mention we also print to G7, with FM would you just print uncalibrated targets and run curves with the Curve2 software same as AM?

 

[gordo]

Gordo, forgot to mention we also print to G7, with FM would you just print uncalibrated targets and run curves with the Curve2 software same as AM?

AFAIK the G7 method is screening agnostic - so it should work the same as with AM screening.

gordon p

 

[Bret Hesler]

I have done G7 with Stochastic, and it does work for the most part. It will not compensate for the hue shift caused by the stochastic screening, but it will match the tonality of an AM oriented G7 proof. If you are looking for a very high level color match, you will probably want to profile the G7 stochastic setup. Otherwise it will be fine for normal color matching.


Bret