ISO Standard Weights

Phish

Active member
Hi all,

We have been trying to achieve a finished print value that is similar if not as close to the standard ISO dot gain settings. We have just had a job with drop shadows which seems to be printing very heavy as well as leaving a ring/band instead of a nice smooth fade off, vignette basically.

We have tried altering our curves but to no advantage, still coming out far to dark and still have the banding in place. We altered the current curve to no effect so i decided to alter the target curve a little. I know this means we have slightly come away from the true ISO dot gain readings but no matter what we tried, we tried altering the CURRENT Curve a few times but to no advantage.

The only thing i can think of now is to try and alter the TARGET Curve, is this right? I was lead to believe that the TARGET should not be touched but as stated above, no matter what we did to the CURRENT Curve, the same effect was happening.

Any advice would be grateful, pulling our hair out now and the boss is not too happy that we can not figure this out.

We are using Harmony to create our Curves, plates used are AGFA Azura with only a simple gum unit to wash out the plates ready for the press.

Is it the customers artwork?

Many thanks for your time and patients.

Phil.
 
Why are you all considering is the Curve?Curve can`t change everything,you`d better check your printing condition first~
 
BTW - it is never the customers art, it is always your workflow

BTW - it is never the customers art, it is always your workflow

Hi all,

Is it the customers artwork?

Phil.

Even if they provided you color separations where you have shadow areas with 400% - there are many ink optimization tools that convert the separation to something you can work with.

Without understanding what you workflow and settings are, anyone would have a hard time suggesting what to do - this is where the G7 method helps you understand where you are and get you where you want to be.
 
Without understanding what you workflow and settings are, anyone would have a hard time suggesting what to do - this is where the G7 method helps you understand where you are and get you where you want to be.

Sorry Michael, I don't see the G7 method being of any specific help in this case.

This seems to be a case of not being able to diagnose the cause(s) of a problem based on the symptoms and possibly not understanding the tools.

Symptoms:
"a job with drop shadows which seems to be printing very heavy as well as leaving a ring/band instead of a nice smooth fade off, vignette basically."
"We have tried altering our curves but to no advantage, still coming out far to dark and still have the banding in place"
"We altered the current curve to no effect so i decided to alter the target curve a little."
"no matter what we did to the CURRENT Curve, the same effect was happening"
"We are using Harmony to create our Curves, plates used are AGFA Azura"

Some questions:
What halftone screening and lpi are you using? (You may have exceeded the plate capability)
Does the problem only occur with this one job or does it occur with all jobs?
Have you checked the customer file to determine if the problem is built in? (You indicate that you haven't checked this)
Does your proofing typically reflect your presswork?
Does the job proof correctly?

In Harmony:

The Target curve is what you are trying to hit - you do not change it.
The Current curve is the press response of your (preferably) unlinearized plate - you do not change it.

Harmony takes the data from the Target curve and the Current curve and calculates a Compensation plate curve. If you've done your initial measurements correctly - i.e. you've given Harmony good data, you seldom need to adjust the final Compensation plate curve that Harmony creates.

Of course this all assumes that the problem originates in prepress. But in this case, the pressroom could also cause the same symptoms to appear.

best, gordon p
 
Last edited:
Hi all,

We have been trying to achieve a finished print value that is similar if not as close to the standard ISO dot gain settings. We have just had a job with drop shadows which seems to be printing very heavy as well as leaving a ring/band instead of a nice smooth fade off, vignette basically.

We have tried altering our curves but to no advantage, still coming out far to dark and still have the banding in place. We altered the current curve to no effect so i decided to alter the target curve a little. I know this means we have slightly come away from the true ISO dot gain readings but no matter what we tried, we tried altering the CURRENT Curve a few times but to no advantage.

The only thing i can think of now is to try and alter the TARGET Curve, is this right? I was lead to believe that the TARGET should not be touched but as stated above, no matter what we did to the CURRENT Curve, the same effect was happening.

Any advice would be grateful, pulling our hair out now and the boss is not too happy that we can not figure this out.

We are using Harmony to create our Curves, plates used are AGFA Azura with only a simple gum unit to wash out the plates ready for the press.

Is it the customers artwork?

Many thanks for your time and patients.

Phil.
Please call and we can talk about your problem. . .Dan Remaley (US) + 412.889.7643
 
Many thanks for the replies and will hopefully give the answers or questions where needed but first some background i think.

Not had to much do with this job except to try and plate for proofing, this is a very rare job that is being WET proofed first instead of digi proofed. After first outputting the job the first time and it was printed, we noticed that the drop shadows appearing had a band to them. To try and describe this 'banding' is that it looks fine until it get the edges at around the 10-8% point. Then for some reason you could see a 'banding' or 'stepping' effect which made it look like it was going down in steps and had a hard edge to it instead of a nice smooth decrement to 0%.

After checking the pdf that was made from Prinergy Evo, everything looks ok on screen except for the fact it is a 4 colour drop shadow instead of a single colour drop shadow. This is something that we decided was not the problem due to us printing just the black plate to find it was happening in that as well as all the other colours separately. I then decided to output the black only plate and check the tints under a glass, interesting thing is that it looked nice on the plate, no visible signs of banding or stepping. A nice decrement of dots and even holding a very small dot of around 2-1%. I even tried to set the job to Trap as it was a 5 colour job, Solid background of yellow, hoping that the dots would do something but no, worth a shot i thought. We then tried the job on separate paper, the job was originally on a Cartridge paper so decided to try it on a Matte paper, same effect was happening.

We then thought that the only thing to try was the curves but unfortunately we did not know where to start as they have been pretty good recently. We have been having issues with print balance but this is something we are getting to.

All i want to do is try and get our print works running with the least amount of fuss, i know it sounds like a dream but i want to make things less complicate for all departments by getting things in sync. We recently went ISO 12647 and installed a proofing system to try and get things in sync that way. I have never been happy with how this has gone, no fault of many but i believe it is something that is still very much a sore subject as the lack of information concerning ink levels and the way it was implemented, is something that has made me try and understand further. Too many people are trying to introduce it without actually understanding it fully.

A concern that a printer had today was when we tried to calibrate our CTP system recently, he did not know what ink levels to go to as he tries to go to ISO but all he has is press sign and an xrite i1 which does not seem to do what it is meant to. Why this i do not know, to me its about reading tint from printed work from unlinearized plates and creating a curve with these as CURRENT and setting the ISO dot gain settings as TARGET.

Where i am coming from is that i do not know if over time and quite a few plate changes over the last 2 years, our curves maybe incorrect and maybe causing this problem but as stated earlier, under a glass, the dots look fine.

Right then, hopefully that has given you a better understanding of the background of our actions etc.

To answer some of your quotes, here goes-

Bloodsaler

'Why are you all considering is the Curve?Curve can`t change everything,you`d better check your printing condition first~'

This is something i suggest at times and can get different responses, how do you get your printers to do this knowing what they say is right? That is no offence to the printer but he only knows what he knows etc and as other people use the same equipment, people know their jobs and work in different ways. Totally understanding where you are coming from as we are very critical of what can go wrong on our side, prepress, and have tried to come up with as many problems and ways to make sure we over come them by knowledge but we can only know what we can study or understand.

Michaelejahn

'Seek ye a G7 expert. Ours is Alvaro'

Got no idea of what your going on about there? Lol.

Have heard people go on about something to do with this G7, i may look into it.

Even if they provided you color separations where you have shadow areas with 400% - there are many ink optimization tools that convert the separation to something you can work with.

Without understanding what you workflow and settings are, anyone would have a hard time suggesting what to do - this is where the G7 method helps you understand where you are and get you where you want to be

We are using Prinergy Evo, the settings have been checked by Kodak via site visits and remotely every so often during the last 4 years. We recently upgraded, well start of this year, to the most recent version of Prinergy Evo, version 5. As for the G7 thing, same as above question.

Gordo

You pop up everywhere, hope your well, many thanks again for your input. Your input concerning linaerizing our CTP was very informative and interesting, i have used it to show around the work place to hopefully get people to understand what i am trying to do.

'What halftone screening and lpi are you using? (You may have exceeded the plate capability)'

We use 175 lpi and 2540 dpi, dot shape of Euclidean but it could be one that sounds familiar, i am at home at the moment and do not have access to the RIP.

Does the problem only occur with this one job or does it occur with all jobs?

Overall most jobs are fine but as stated above, i want to recalibrate the press now i have a better understand of what these engineers have attempted to do but seem to have caused problems in some ways. We have had problem with drop shadows or vignettes but after going to a different curve, they have not been to bad. I still think with the technology and equipment we have, we should be getting better, a lot better. It is just getting the time, resources and people to understand what and where i am coming from and trying to do.

Have you checked the customer file to determine if the problem is built in? (You indicate that you haven't checked this)

I have only checked the pdf that prinergy created due to time, i had to change shifts etc so i am trying to get a better understanding for everyone involved in this. What i have seen seems ok but what you get on screen and digi proof does not always reflect in what comes off the press, for what every reason.

Does your proofing typically reflect your presswork?

Usually it is pretty accurate but the paper we use on the proofing machine does not reflect the paper we use on press. I find that even though the profiles of different paper have been inputted into proof sign, Cartridge paper is dull and our proofing paper is semi glossy which looks odd. Passes the proof sign, well used to but recently been having a problem with that, maybe a dodgy roll of paper. This is an area that is a bit open to idea, so to speak. What i understand is that the press use press sign to read the setting etc to balance and achieve ISO readings but i do not know if this has been either working right, followed right, understood right or even implemented right as it is a totally separate department to ours.

Does the job proof correctly?

Yes off digi but obviously not WETS.


Danremaley

I live in England dude and i do not think work would appreciate the long distance phone call but thankyou very much for the offer.

Again, many thanks guys, sorry to have gone on but i hope you all understand a bit more and if you can help further, wow, thankyou.

Phil.
 
@Phish/Phil.

Gordo You pop up everywhere,

You're right! :) I must stop the pop! Too much time on my hands.

Some thoughts.

G7 is a method (don't know if ISO has adopted it) for building plate curves to achieve grey balance. I don't think that's your problem which is why I wrote that G7 wouldn't help you.

Unless you are using wooden printing plates - 175 lpi at 2540 dpi shouldn't be a problem. The dot shape of Euclidean (round/square/round) while, IMHO not ideal, is not the problem.

After reading your answers to the various questions and suggestions in this thread, my feeling is that you might want to go back to basics. Juggling bits of info and tweaking the process here and there can quickly put you in an unstable confused situation.

There are some basic principles that I go by that helps me chart a path through the chaos - maybe they can help you.

1) ISO 12647 is based on a linear positive film workflow. If you run linear CtP plates to the appropriate densities with a 175 lpi screen then you shouldn't be very far off the ISO press curves curves unless there's a problem with the press or inks.

2) If you have a proof that is certified as ISO 12647 compliant - e.g. a proof from another printer - then, your presswork color should align to that proof using the appropriate densities with a 175 lpi screen unless there's a problem with the press or inks.

3) The job of the press operator is NOT to make color on press. It is to lay down a film of ink at a specific thickness (CMYK) and to trap one ink into another at a specific efficiency (RGB). That can be measured and verified objectively.

4) The press operator also needs to maintain the integrity of ink laydown (no mottle or voids) as well as the integrity of the halftone dots (no slur, doubling, slinging, etc.) Those characteristics can also be verified objectively.

5) If the presswork is reliable and consistent, then you can build curves to refine your tonal alignment to the proof. If your presswork is not - then you cannot. You cannot use plate curves to fix press problems.

Oh, here's a product plug - forget long distance calls. Use Skype - it's free and works very well indeed.

best, gordon p
 
As you can`t find any problem in pdf file and in plate,I think you`d better check your press first.You can print a big 50% area sample for each unit,and find whether has a band in it~If it does,then correct the press setting.And also measure the TVI curves.
And you can also check the ICC in your prepress workflow and proof system,the ICC also casue some banding problem~
 
Your problem is in the low %, It would be interesting to see your compensation curves, especially 20-0%.
Some times the measuring devices just don't do it for you and you will have to look at your curve and use common sense.
Also do consider using a coarser or hybrid raster for a smoother fade out of low %. (If you don't have that option adding a certain amount of "noise" on drop shadows in indesign to some degree will hide the banding problem as it tricks the image into looking like a hybrid raster in the fade zone)

One more question pops up in my mind. You are talking of a wet proof. Is the wet at up to production speed? Are the plates drying and then re-printed so you get a corona?
 

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