Linearizing out plates and recalibrating?

[Phish]

Hi all,

i am new to this place so firstly, hello to you all, i am Phil and work in a place called SEM Envelopes Ltd in Derby England. It is a small to medium sized print shop employing around 50 people.

The problem?

Keeping the colours to an iso standard.

We had recently switched to ISO 12647 and had everyone (more than once) re-calibrated or set up to print to this standard. We have had the Kodak Lotem done what seems like twice a month for the past 3 months, trying to keep its colour etc.

The main problem is that with all these altercations to our output device, i have no idea what's been done as well as neither understanding the manual as to how to re-calibrate it myself. Alot of the people that have come in have re-calibrated the machine without anyone watching, so no idea if what i am doing is right?

Can anyone try and put it into plain english as to how to go about this process? What and where to look etc?

We are using prinergy 5 which inturn is using Harmony 1.2.1.1.

Can recalibrate film no problem, is this simular? I am not used to 3 curves (Current/Target/Calibration)

Many thanks for your time, if any other information is needed then please ask.

Phillip.

 

[seejay]

Hi Phil,

In my experience, it is very unusual for a CTP device to 'wander'. Generally if/when the plate has been linearised then it tends to remain stable provided your processor/chemistry etc. is good.

As such, my first recommendation would by to measure and check your plate to see if it is wandering - we tend to do this twice a day by measuring a calibration patch on the plate (20,40,50,60,80). Measuring and logging this will determine whether your plates are imaging and processing consistently. Once you have established whether this is the case then you can start looking at your press processes.

 

[gordo]

There are two "calibrations"

1- the initial set up of the laser intensity on the CtP device. This is done to achieve a robust dot on the plate. The resulting plate may, or may not be linear (likely not).

2- The application of a tone reproduction curve to the plate to achieve the required tone reproduction in the presswork. This may or may not be a curve to linearize the plate. Unlike a film workflow, there is no need to linearize the plate. There is only a need to have the appropriate tones on the plate that provide the desired tone reproduction in your presswork.

In Harmony "Current" typically means the tone reproduction you get on press with plates calibrated as per #1 above. "Target" means the tone reproduction that you want to achieve on press (could be previous presswork or published ISO curves). "Calibration" is the curve that Harmony creates from the "Current" press response and the desired "Target" press response that will be applied to plates.
Harmony is typically used once to build your curves. For a complete explanation of how Harmony works go here: http://qualityinprint.blogspot.com/2010/02/principle-of-dot-gain-compensation.html


Once calibrations #1 and #2 are done, then as Seejay said, things should remain pretty stable. You monitor the plates to confirm that stability, and based on that you'll likely need to look at other places, like your possibly proofing and especially presswork for inconsistent performance. You should not be using plate curves or laser adjustments to correct for an unstable pressroom.


best, gordon p

 

[danremaley]

Hi all,

i am new to this place so firstly, hello to you all, i am Phil and work in a place called SEM Envelopes Ltd in Derby England. It is a small to medium sized print shop employing around 50 people.

The problem?

Keeping the colours to an iso standard.

We had recently switched to ISO 12647 and had everyone (more than once) re-calibrated or set up to print to this standard. We have had the Kodak Lotem done what seems like twice a month for the past 3 months, trying to keep its colour etc.

The main problem is that with all these altercations to our output device, i have no idea what's been done as well as neither understanding the manual as to how to re-calibrate it myself. Alot of the people that have come in have re-calibrated the machine without anyone watching, so no idea if what i am doing is right?

Can anyone try and put it into plain english as to how to go about this process? What and where to look etc?

We are using prinergy 5 which inturn is using Harmony 1.2.1.1.

Can recalibrate film no problem, is this simular? I am not used to 3 curves (Current/Target/Calibration)

Many thanks for your time, if any other information is needed then please ask.

Phillip.

Are you changing the plates because of changes to dot gain values on press?
[email protected]

 

[Phish]

Firstly, many thanks for the replies.

Will go in order of replies if thats ok?

1) Seejay.

Thanks for the idea of checking the tint value readings from the colour bars that we use. I am in the process of finding a decent plate reader to take these readings, any good idea's?

I would have thought that with general maintenance and 2 yearly services, the lasers that create the dots should remain stable and not wonder too much even if we have been using this machine for around 4 years and when it was purchased by us, it was reconditioned. It was sold by Kodak which again should give you confidence that it has been checked etc so not convinced that our Lotem 800 is the problem.

As for what you said about the processor and chemistry, we are using an AGFA Asura plate that has been set up to be used on our Lotem. Onced exposed, the plate is then fed to a processor which simply washes out the non exposed area/emulsion and aplies gum, no chemicals are used except gum. This should not effect the plate in any way that i know of, one thing that has crossed my mind is that by using recycled gum, would the strength deteriate before the actual time allocated. Suppose that testing a plate daily with a plate reader will provide this information.

2) Gordo.

I have noticed you popping up all over the place recently, well all the places i have looked at concerning this issue anyways. I recently joined Bloggers as i wanted to read your blogs on there as i am finding these useful, will confess that i am lost a little of the time but i am trying to learn again after so long. Alot of information to take in aswell but where there is a will there is a way.

"1- the initial set up of the laser intensity on the CtP device. This is done to achieve a robust dot on the plate. The resulting plate may, or may not be linear (likely not)".

This was done when we had the plates changed recently, this is the usual requirement, i presume, of changing plates? As for it being linear, i will come to this later.

"2- The application of a tone reproduction curve to the plate to achieve the required tone reproduction in the presswork. This may or may not be a curve to linearize the plate. Unlike a film workflow, there is no need to linearize the plate. There is only a need to have the appropriate tones on the plate that provide the desired tone reproduction in your presswork."

This is something that i am interested in, i am trying to totally understand this and will read the link that you posted with your reply soon. We recently had a independant technician come in and give us the answers to the questions we have been trying to figure/find out.

What was confussing for us was that non of us knew totally how harmony worked, we seem to have loads of different curves but no idea of what they actually did or used for. I have tried reading the manual but whether due to my inability to understand it in a way to satisfy the needs of the required circumstances at hand or just it did not make sense, lol. I would class myself as handy with a computer and find these problems interesting so i asked for someone to come in and explain what was actually happening and how to understand the software that runs the colour/tonal reproduction on the plates. I now feel more reassured within myself of the understandings and how to use the software but what i was told and what you have mentioned a couple of times on various websites is the used of only one curve and not the 2 that i was shown.

The senario went-

Over the last month or so we have been having a problem with vignettes in which we was getting a banding effect or a sudden stop in the gradual tonal reproduction. We have tried to combat this by adjusting the curves in harmony but to no great effect. We have got by but i like things to be right so there can be no come back at all, if a job is worth doing etc. Due to also recently introducing ISO 12647 into the work place, we are not getting a match to our calibrated proofing system and our press. Everything, especially the yellow and magenta are out on mid to low tonal areas, like snow etc from press to proof. The proof looks great but the press is just not right. after seeing the readings from proofmaster i can see why. So with the information provided by proof master we are trying to correct the curves.

When the technician came in we outputted a plate on what we thought was the correct PLATE curve and also PRINT curve, the readings was not great. We then outputted a plate on just the PLATE curve, i was then informed that this should be a linear plate and all the tint readings should match or close enough, to a maximum of 2%. Again, these were not great so he said to output a plate using not PLATE curve or PRINT curve as then he could take readings and create a plate curve to linearize our plate. During these outputs we noticed the banding effects in gradients/vignettes. Once the readings were taken we then created the PLATE curve by putting the reading we had just taken into the CURRENT curve and then put a linear setting into a TARGET curve eg 10 20 30 40 etc. We then created the Calibration curve by linking these 2 curves. We now had our linear PLATE curve which was put in as default into Prinergy. We then outputted some plates and took a reading from these printed sheets and created a new PAPER curve on harmony. The readings from the printed sheets was the CURENT CURVE and the ISO 12647 standard as the TARGET curve which inturn created our new PRINT curve. Once again, we then set this as default into Prinergy as its PRINT curve.

Wow, been a long day and that took some work, lol.

What has confused me is that with reading, or is it the way i am understanding it, some of your posts online over the last couple of days, you have said you should only have to use one curve and not two. Did what we did mean we used two curves? A PLATE curve to actually linearize the plate and then a PAPER curve to create the PRINT curve? The way i am understanding your posts are just output a plate with large tonal areas that can be easily read straight from having the laser power set to a surficiant power setting to create the required dot on the plate. Take these readings and print straight to paper and then create your PAPER curve which in turn would create your PRINT curve to be used in Prinergy. There would be no use in a PLATE curve as you have just outputted using the basic default settings after setting the laser power, is that right?

3) Danremaley

"Are you changing the plates because of changes to dot gain values on press?"

Hopefully what i have put above gives you the idea of what you need?

We are due to have a service on the press as well which hopefully will sort out a few issues aswell.


Once again, many thanks for your time and hopefully hear from you soon.

Phil.

 

[danremaley]

Hi all,

i am new to this place so firstly, hello to you all, i am Phil and work in a place called SEM Envelopes Ltd in Derby England. It is a small to medium sized print shop employing around 50 people.

The problem?

Keeping the colours to an iso standard.

We had recently switched to ISO 12647 and had everyone (more than once) re-calibrated or set up to print to this standard. We have had the Kodak Lotem done what seems like twice a month for the past 3 months, trying to keep its colour etc.

The main problem is that with all these altercations to our output device, i have no idea what's been done as well as neither understanding the manual as to how to re-calibrate it myself. Alot of the people that have come in have re-calibrated the machine without anyone watching, so no idea if what i am doing is right?

Can anyone try and put it into plain english as to how to go about this process? What and where to look etc?

We are using prinergy 5 which inturn is using Harmony 1.2.1.1.

Can recalibrate film no problem, is this simular? I am not used to 3 curves (Current/Target/Calibration)

Many thanks for your time, if any other information is needed then please ask.

Phillip.

I personally like to make the plate linear, because, I like to look at vignettes and 1-2-3% dots to be sure they measure correctly. Sometimes (like with positive plates), the set-up guy, over exposes the background, to keep it clean, reducing the 50% file dot to 44-45% on the plate and the highlight dots 1-2-3% are blown out! Also if I print a linear plate, I know from experience, a new press will print with around 14-16% midtone gain (with a good pigment ink), so I have a base line. Here's my 3rd. and most important reason, if I ever change plate manufacturer I only need to linearize the new plate and all my previous curves Work!
Dan Remaley 412.889.7643

 

[gordo]

What has confused me is that with reading, or is it the way i am understanding it, some of your posts online over the last couple of days, you have said you should only have to use one curve and not two. Did what we did mean we used two curves? A PLATE curve to actually linearize the plate and then a PAPER curve to create the PRINT curve? The way i am understanding your posts are just output a plate with large tonal areas that can be easily read straight from having the laser power set to a surficiant power setting to create the required dot on the plate. Take these readings and print straight to paper and then create your PAPER curve which in turn would create your PRINT curve to be used in Prinergy. There would be no use in a PLATE curve as you have just outputted using the basic default settings after setting the laser power, is that right?

Unless you have have a unique, very special requirement, you should only use one curve - what I call a press (or print) curve. The purpose of that curve is to create the tone reproduction you require in your presswork.

The job of your CtP is to image plates consistently. It doesn't matter if a 50% request results in, for example, a 45% or a 57% on the plate. What matters is that every time you request 50% that it delivers the same tone. If your CtP imaging is not consistent then you cannot use any kind of curves.

In a CtP workflow, if your plate imaging is not inherently linear then you have two choices.

Choice 1 - First create a curve to make the plate linear ( a plate curve). Then create a second curve to be applied on top of the linearizing curve to create the dots on plate that you need in order to achieve the tones on press that you need (a press curve).

or

Choice 2 - Since the plate imaging is consistent (though not linear) simply create one curve to create the dots on plate that you need in order to achieve the tones on press that you need (a press curve).

With Choice 1, linearizing the plate is redundant since it will be overridden by the second curve. It does not provide any benefits. But it does make the workflow more complicated and hence make more opportunities for mistakes. It can also cause shadestepping (banding) in vignettes.

The laser power setting is to create a robust dot on the plate - not to linearize the plate, nor to achieve specific tones.

It helps to ask yourself exactly what is accomplished by linearizing the plate before applying a press curve.
Is it to bring the plate imaging to a specific status? Well, that should be the case without a linearizing curve. And if the CtP is so unstable that it does not have a consistent status then it is not possible to build linearizing curves.

RE: "I have noticed you popping up all over the place recently, well all the places i have looked at concerning this issue anyways. I recently joined Bloggers as i wanted to read your blogs on there as i am finding these useful, will confess that i am lost a little of the time but i am trying to learn again after so long."

Yes, I'm quite noisy.

I started my blog because I was so frustrated at the lack of clear and accurate information about many of the basic issues in our industry. It caused me a lot of pain, and I've seen it cause pain with many printers.

Do not believe what I've written just because I wrote it. Look at my reasoning, and my arguments, then look at the arguments against what I say and make up your mind as to what is the right path accordingly.

best, gordon p

 

[gordo]

I personally like to make the plate linear, because, I like to look at vignettes and 1-2-3% dots to be sure they measure correctly. Sometimes (like with positive plates), the set-up guy, over exposes the background, to keep it clean, reducing the 50% file dot to 44-45% on the plate and the highlight dots 1-2-3% are blown out! Also if I print a linear plate, I know from experience, a new press will print with around 14-16% midtone gain (with a good pigment ink), so I have a base line. Here's my 3rd. and most important reason, if I ever change plate manufacturer I only need to linearize the new plate and all my previous curves Work!

OK I'll take #2 and #3

If you print with a linear plate and you're using an FM screen you're not going to get a 14-16% midtone gain since midtone gain is dependent on several factors including the screening.

The thing is that it does not matter what your mid tone gain is (in fact mid tone gain hasn't been published as a spec in North America since 2006). Dot gain is not a base line. The important thing is that the press exhibit good ink transfer, minimal deformation on the halftone dot, etc., etc.

If you change plate manufacturers, yes, you will need to create a new linearizing curve then you can simply apply your previous curves.

If I change plate manufacturers I will need to create a new curves to achieve the same plate dots that I had before. If I had 4 curves (pretty typical) then that means four new curves for me (three more than you). About 20 minutes more work for me. Agreed. But in the end, I will have a simpler workflow - total of four curves for me compared with your total of five curves - with less chance of errors and shadestepping issues caused by curving curves for me.

best, gordon p

 

[seejay]

Hi Phish,

we use the x-rite ic plate 2 to measure our plates - we've found that its a very good, easy to use peice of kit.

With regard to the Asura plate, we have been testing this for the last month and a half. Our tests have proven very successful, with the plate showing no signs of instability - our plan now, is to switch our production 100% over to Asura in the new year (we currently use Agfa Elite plates).

 

[Phish]

Hi all,

Many thanks for the replies once again, some great response which i have read and appreciate very much. I want to try and do this calibration thing myself and i am interested in trying out both ways of doing it, eg. Using only 1 curve and also using the 2 curve process.

We are looking into buying an X-Rite plate dot meter so we can read the plates properly and hopefully, away we go. One idea that has been brought up is putting a tint gauge somewhere on the plate in a non print area so we can check the plates every time they come out the processor and CTP. Failing that, we can just take a reading from the colour bars we use.

One thing today that has got our brains going is how well is the gum washing/developing the plates, is it too robust or do we need to change its speed etc. I am going to look into this and hopefully find out some answers, wether it be it off the internet or from the customer support team at AGFA, does not matter really as long as i know it is optimized for our plates. We are using an AGFA Azura C125 plate processor and with that Azura TS Gum, this equipment has been set up for us so i am desperate to find out anything i can about this processor that is not in the manual, such as the optimum speed and temperature of the unit to produce consistent results.

Other than that i can not think of anything else that can be effecting the plates in anyway to make them so inconsistent. I have a feeling that we are a studio that is constantly chasing our press and it should be the other way round or atleast a bit of both and not all one way. Maybe the case in a lot of work places but when something is wrong with a colour or job the first place the fellow workers go into to find out whats happened is Repro. Can we fix this and that and hence why so many curves i dear say have been made over the last 6 months or so.

Well, i am off here for the time being, once again, many thanks, all of your help, no matter how big or small, has proven to be a great influence in a good way, thankyou. I will keep a look out on these forums just incase i maybe able to help anyone like you have me.

Phil.

 

[DCurry]

I doubt the issue is with your plate processor, simply based on how it and the Azura plate work. There is no chemistry or development to go wonky - the processor is simply scrubs the non-image (non-exposed) area off the plate and applies a protective film of gum. Even if the pressure is off, any unexposed areas on the plate will clean up on press when water hits the plate (if you take an unexposed plate and rub it with a wet finger, you'll see the emulsion comes right off quite easily). This is a real advantage of this system - no chemistry or developer settings to be concerned with.

When you read your plates, it is a good idea to take a damp cloth and scrub the gum off the colorbar that you will read with your plate reader. You can rub it pretty heavily to assure you are getting a reading of the dots on the plate, not the gum (which gets a blue tint and can affect your plate readings). This advice was given to me by our Agfa plate technician when installing our Azura setup.

 

[danremaley]

OK I'll take #2 and #3

If you print with a linear plate and you're using an FM screen you're not going to get a 14-16% midtone gain since midtone gain is dependent on several factors including the screening.

The thing is that it does not matter what your mid tone gain is (in fact mid tone gain hasn't been published as a spec in North America since 2006). Dot gain is not a base line. The important thing is that the press exhibit good ink transfer, minimal deformation on the halftone dot, etc., etc.

If you change plate manufacturers, yes, you will need to create a new linearizing curve then you can simply apply your previous curves.

If I change plate manufacturers I will need to create a new curves to achieve the same plate dots that I had before. If I had 4 curves (pretty typical) then that means four new curves for me (three more than you). About 20 minutes more work for me. Agreed. But in the end, I will have a simpler workflow - total of four curves for me compared with your total of five curves - with less chance of errors and shadestepping issues caused by curving curves for me.

best, gordon p

>>>>Yes I know, FM more like 28% gain, (with a linear plate) I was speaking of AM screening.
>>>> I disagree, midtone gain is a base line, for me when I'm - comparing one press to another, one ink to another, etc. and it's included with the ISO standard tone scale. The default setting in Photoshop RGB>CMYK is around 20%. You could measure a 3% but what would it tell you? There's very little change, unless packing, pressure, rollers, etc. are extremely wrong. 50% shows small differences. Felix Brunner <www.systembrunner.ch> uses the 50% gray patch for the best color control system in the world! Brunner has written a lot about measuring color, he says "80% for color variation is caused by "dots", only 20% is caused by "solids"! So, what do you measure? 20% of the problem, you won't be successful, and he doesn't care if it's Lab or density.
>>>> If you don't linearize first, then how do you know what each plate value % is? If you changed to a Fuji plate, maybe positive to negative, your existing curves won't work, UNLESS you measured and plotted the 'new' plates to the old readings. Which is ok, I just like working from a known standard. (I think were saying the same thing). I worried about people that never adjusted the platesetter from the initial set-up, (and only have ONE curve for all colors). The big dis-service is Creo sold platesetters for 150,000 and didn't include anything to measure the plates with. . .now we have no process plates and you can't measure them without a very expensive device, I'd like to talk to the engineer that designed that product! Edward Demming must be turning in his grave. . .produce quality? You cn't measure it!

 

[gordo]

>>>>Yes I know, FM more like 28% gain, (with a linear plate) I was speaking of AM screening.

Change the AM lpi and you change the dot gain. Because of how dot gain is measured you could have an unusable press condition yet still have the correct measured dot gains.

>>>> I disagree, midtone gain is a base line, for me when I'm - comparing one press to another, one ink to another, etc. and it's included with the ISO standard tone scale.

It would be great if you could explain that ISO standard tone scale 'cause the ISO people don't explain it.
Dot gain is useful as a process control metric. But it is not very useful as a target. To be clear, when I look at an ISO curve I don't see it as target dot gains - I see it as target tone reproduction.

The default setting in Photoshop RGB>CMYK is around 20%. You could measure a 3% but what would it tell you? There's very little change, unless packing, pressure, rollers, etc. are extremely wrong. 50% shows small differences. Felix Brunner <www.systembrunner.ch> uses the 50% gray patch for the best color control system in the world! Brunner has written a lot about measuring color, he says "80% for color variation is caused by "dots", only 20% is caused by "solids"! So, what do you measure? 20% of the problem, you won't be successful, and he doesn't care if it's Lab or density.

That has nothing to do with whether you should linearize your plates or not.

>>>> If you don't linearize first, then how do you know what each plate value % is?

You measure the plate.

If you changed to a Fuji plate, maybe positive to negative, your existing curves won't work, UNLESS you measured and plotted the 'new' plates to the old readings.

In both cases, linearizing the plate or not linearizing the plate, if you switched plate vendors you will have to measure the dots on the plate in order to rebuild your curves. You to create a linearizing curve, me to create a press curve.

Which is ok, I just like working from a known standard. (I think were saying the same thing).

Don't confuse "uncalibrated" with "unknown"
You've made me realize that the terminology may be creating confusion.

When the CtP device is set up by the installing technician it is "calibrated" i.e. set to a known imaging condition. The result may or may not be a linear plate but it has known tone values. Those tone values on plate can then be used to monitor the consistency of plate imaging over time. There is no need to create a linearizing curve in order to have this process control tool.

I worried about people that never adjusted the platesetter from the initial set-up, (and only have ONE curve for all colors).

Standard targets like ISO are based on a one curve for all colors. That was how it was in the film days, and until recently in the CtP world. It works very well. What I worry about is printers using plate curves for individual colors in order to compensate for ink issues, and press condition issues. Using different curves for each color, if it's going to be done, has to be done with extreme caustion and understanding as to why it is being done.

The big dis-service is Creo sold platesetters for 150,000 and didn't include anything to measure the plates with. . .now we have no process plates and you can't measure them without a very expensive device, I'd like to talk to the engineer that designed that product!

Well, I bought a table saw recently and was not given a tape measure. So what? Why would a CtP vendor include a measuring device when the customer may already have one, or prefer a different brand? Do other CtP vendors give away plate readers with their CtP devices?

I'll let Kodak speak for their no-process plate. Suffice it to say that there are thousands of DI presses in the field where you can't measure the plates either. You're saying that they should not have designed and sold those presses because you can't measure the plates?

Edward Demming must be turning in his grave. . .produce quality? You cn't measure it!

Well, yes you can measure it. You just don't have to apply a linearizing curve first.

For a complete discussion on this topic go here: http://printplanet.com/forums/computer-plate/22416-poll-do-you-linearize-your-plates

There's also a 4 part explanation on this topic on my blog: Quality In Print: Search results for linearize

best, gordon p

 

[SteveAgfa]

Dan mentions...

<snip>
. . .now we have no process plates and you can't measure them without a very expensive device, I'd like to talk to the engineer that designed that product! Edward Demming must be turning in his grave. . .produce quality? You cn't measure it!
<snip>

Yet another reason for Agfa's Azura TS chem-free plate's success.

You can measure the dots with a standard device... although with
the plate's wide imaging latitude and resultant image consistency,
some users swear they don't need to measure the dots afterall.

Regards,

 

[KevinC@EFI]

I'll let Kodak speak for their no-process plate. Suffice it to say that there are thousands of DI presses in the field where you can't measure the plates either. You're saying that they should not have designed and sold those presses because you can't measure the plates?

Well, yes you can measure it. You just don't have to apply a linearizing curve first.

Thanks Gordo - you're spot-on here. No, you can't measure the plate curve individually from the press curve with ThermalDirect - but they always work in combination in the end - even for a "normal" plate. Believe it or not, Steve quotes the exact reason this shouldn't be a huge concern for ThermalDirect (of course he's speaking of Azura, but the reasoning and technical support for it are the same):

<snip>
... although with the plate's wide imaging latitude and resultant image consistency,
some users swear they don't need to measure the dots afterall.
</snip>

Thermal Direct gets rid of the chemical development step and the resulting variability of that process. The one-time setup involves measuring the dot-gain curve on press, but after that it's set and doesn't need to be tweaked like an old processed plate. It's amazing how often this whole subject comes up in the sales process (due no doubt to the counter-marketing of our competitor , but it's funny when I ask "do you measure your plates regularly today, and do you even own a plate densitometer" the answer is quite often "no".

I'm not saying it's never a concern or question - just that our thousand(s) of customers using Thermal Direct globally are quite happy with the benefits of the system, and very quickly get past the mindset that plate processing variation is part of the equation like it was in the old-days.

Kevin.

 

[Phish]

Morning all,

Wow, what a response from a question that i did not think had too many people interested in it, how wrong was i, lol. Read some fascinating stuff either in reply format or by links contributed to by members etc. Your all stars on here and no matter how little or how much you have contributed to answering my question, i am grateful.

Been thinking long and hard about what type of calibration to use in our pre press studio on the Lotem 800 Fibre Optic CtP. As we are a relatively small print works with only one Litho Press and one CtP machine to get right, the logical one to use will be the One Curve policy. If this does not work then the 2 curve option is still open to us. Had a word with our press guys and i am hoping to get the ball rolling on this asap but firstly all the issues on the press have to be sorted out, never realized that our works press was in such bad state yet it is only 4 years old, what constant running does i suppose. They are saying that once all the littler & big things have been fixed and checked it will take about 1.5 hours per unit to get that unit ready to be as good as it is going to get, wow!!!!!!!!! With 5 units that a long time before we even start to print. Can not see the test print taking that long to print, should only need around a run of a few thousand sheets to balance etc i would say.

Looking forward to this when it does actually happen, hopefully sooner rather than later. Will try and keep this thread up to date when we things do start etc.

Many thanks again.

Phil.

 

[SteveAgfa]

Phil:

RE:

<snip>
One thing today that has got our brains going is how well is the gum washing/developing the plates, is it too robust or do we need to change its speed etc. I am going to look into this and hopefully find out some answers, wether it be it off the internet or from the customer support team at AGFA, does not matter really as long as i know it is optimized for our plates. We are using an AGFA Azura C125 plate processor and with that Azura TS Gum, this equipment has been set up for us so i am desperate to find out anything i can about this processor that is not in the manual, such as the optimum speed and temperature of the unit to produce consistent results.
<snip>

An Azura system is typically a "set-it, and forget-it" installation.

There is a wide exposure latitude, so changing your exposure won't cause much impact -
other than dropping below the fusing threshold. There is no real clean-out variable in the COU.
Please work with your local Agfa rep. to return to the installation settings. Azura should be your
constant and control.

Regards,

 

[fiatlux]

An Azura system is typically a "set-it, and forget-it" installation.

There is a wide exposure latitude, so changing your exposure won't cause much impact

Kodak should hire you to do their plate marketing.

First you say that being able to measure the plate is the reason for choosing Azura over the Kodak plate. Then you imply that there's no need to measure the Azura plate after being set up since it's a "set-it, and forget-it" installation.

Impeccable logic.

FL

 

[KevinC@EFI]

Kodak should hire you to do their plate marketing.

First you say that being able to measure the plate is the reason for choosing Azura over the Kodak plate. Then you imply that there's no need to measure the Azura plate after being set up since it's a "set-it, and forget-it" installation.

Impeccable logic.

FL

Maybe I should be hiring you to do ours...

 

[SteveAgfa]

Hi Fiat:

The measurement ability of Azura relates to the context of the thread.

The practical aspect of a high image contrast plate such as Azura TS is
the ability to QC the content - ie - are the logos and images high res, is
the plate going on the correct cylinder, etc. I've posted an image comparison
before.

Compared with on-press clean-out plates, there is no practical impact
to the pre-imaged, post-imaged or post-clean-out image of Azura whilst
hanging around the plant en plein aire. Our worthy competitors must
limit time exposed to white light; even though the plate might have a
nice imaging latitude, it remains sensitive to ambient white light, unlike
that of Azura TS.

If you or anyone else is interested in a comparison, I'd recommend
running the two plate types side-by-side. Let the plant choose.

Regards,