printing with out dotgain

[Magnus]

I think it is extremely likely that anyone who has the skill set and training (hmm, I've trained a few) to measure the dots on a plate WOULD and SHOULD have at least a passing knowledge of WHAT makes dots on plates change and how to fix it.
Worst case - try a new box of plates.

Alright. Since English isn’t my first language, I might be misunderstanding what you’re trying to convey.

I’ve also trained a few colleagues on how to check plate consistency using the Techkon Spectro Plate. However, neither I nor those I’ve trained have the technical expertise to resolve deeper issues within the CTP system. We do know how to carry out routine maintenance, but I’ve seen many instances where that’s not enough to solve the problem.

I must say, I’m both surprised and somewhat amused that “linearizing the CTP” was such a hot take.

 

[Repro_Pro]

It is my experience that applying a correction curve on top of an existing curve produced unexpected results.
Applying just one Tone Reproduction Curve always worked well.
However, perhaps it was an over-complicated calculation for our particular old rip (Brisque).

 

[Magnus]

It is my experience that applying a correction curve on top of an existing curve produced unexpected results.
Applying just one Tone Reproduction Curve always worked well.
However, perhaps it was an over-complicated calculation for our particular old rip (Brisque).

I have not experienced any issues with this in Apogee for instance. There is a special section for CTP linearization curves.

 

[Magnus]

I forgot about a couple of more arguments for linearizing the CTP:

• A site has multiple CTPs, often different generations and sometimes even different fabrications. Then you want to align the CTPs to avoid variotions in print or multiple TVI curves,
• You upgrade or exchange your CTP system. If your CTP is linearized you can now just linearize the new system and your good to go, no new TVI curves are needed.
• You change the plate vendor. Different plates have different charactizations, just linearize the new plates and you are good to go.
• You change developer type or chemicals. Relinearize the plates and you are good to go.

 

[gordo]

I forgot about a couple of more arguments for linearizing the CTP:

• A site has multiple CTPs, often different generations and sometimes even different fabrications. Then you want to align the CTPs to avoid variotions in print or multiple TVI curves,

That way if you have 4 sites - instead of 4 TVI curves then you have 8 different curves - 4 to linearize and 4 TVI curves.

• You upgrade or exchange your CTP system. If your CTP is linearized you can now just linearize the new system and your good to go, no new TVI curves are needed.

Then you have 2 curves instead of just 1

• You change the plate vendor. Different plates have different charactizations, just linearize the new plates and you are good to go.

Again, 2 curves instead of 1

• You change developer type or chemicals. Relinearize the plates and you are good to go.

Again, 2 curves instead of 1

I guess I've just seen too many shops dealing with issues using 2 curves instead of 1

 

[SheetSqueezer]

I thought the standard process was as follows:

1) Linearize the Imagesetter and measure plate output
2) Add compensation curve for plates (if necessary)
3) Print linearized test sheets on press
4) Add compensation curve for press (if necessary)

2 total (expected) curves: 1 for the Imagesetter, 1 for the Press

Random, periodic measuring is then up to PrePress and Press, to make sure actual results align with expected results.

 

[gordo]

I thought the standard process was as follows:

1) Linearize the Imagesetter and measure plate output
2) Add compensation curve for plates (if necessary)
3) Print linearized test sheets on press
4) Add compensation curve for press (if necessary)

2 total (expected) curves: 1 for the Imagesetter, 1 for the Press

Random, periodic measuring is then up to PrePress and Press, to make sure actual results align with expected results.

Yes, some vendors would have you do this - but that does not make it right.

In any case, the question about linearizing the plate is not what the OP asked about.

I think I'll make this a topic for the next "Overtime" post where I can use colorful graphics to answer the question of linearizing plates.

 

[Magnus]

That way if you have 4 sites - instead of 4 TVI curves then you have 8 different curves - 4 to linearize and 4 TVI curves.

Then you have 2 curves instead of just 1

Again, 2 curves instead of 1

Again, 2 curves instead of 1

I guess I've just seen too many shops dealing with issues using 2 curves instead of 1

There’s nothing wrong with having multiple curves if they serve different purposes. Creating or updating TVI curves on-press is a far more time-consuming and costly task than re-linearizing a plate curve, it only takes about 20 minutes for one person to do the latter.

Applying this approach to another example - say, aligning three identical-model inkjet printers (which, as we know, vary slightly out of the box) — you’d follow two steps (or more depending of software and approach):

1 Printer linearization (equivalent to the plate curve)
2 Printer ICC profiling (equivalent to the TVI curve)

If you linearize all three printers first, you only need to measure and generate one ICC profile, then use that same profile on each machine. Maintaining consistency by relinearize when needed.

The assertion that applying one curve on top of another in the RIP leads to problems is baseless and lacks empirical evidence.

 

[tnims68]

You need to fingerprint your press.......