Dotgain compensation

[sornchai]

When I created printing press icc profile by Fiery. Is there a dotgain compensation built into the profile or do i created dotgain curve at ctp stage?
Thank you so much

 

[Gianni_S]

Hi,
an icc profile is something more complex than a dotgain curve.
In a icc you have several information such TIL, trap, gray balance, color and tonal response and also dotgain.
So when you are creating your icc it compensate for compensation on a specific paper.

 

[Asures]

Dot Gain Curves are generally for the press. An ICC Profile is to force the proofing system to replicate the printed piece(s) once calibrated.

 

[Correct Color]

Good morning,

Well... it depends.

But to break it down a bit, and to be completely accurate: No, "dotgain compensation" is not "built into" an ICC profile.

There are, however, a lot of terminologies that overlap in this industry and a lot of people also use one terminology when they really mean another. People often talk about "calibrating" a device, when what they actually mean is "profiling" a device, and even the word profile can refer to an ICC profile alone, or some broader meaning of a particular media profile.

So...

The way the basic process works is: To make a complete media profile, you first have to create what I call a "machine state", and then a characterization of the machine printing in that state.

The machine state should include all the information of a machine in any given state; anything that is unique to the condition you're trying to characterize, and it's that condition that should contain your neutral tone curves (translated as dotgain compensation.) Other elements of a machine state would be white point, media type, individual ink chroma values and densities, total ink densities, etc.

Once you have the machine state created, the characterization is then the ICC profile. You print a set of patches using the machine state you created, and read them with a spectrophotometer. Then you run those readings through ICC profiling software and you get an ICC profile, which is a characterization of that machine printing in that state. And the ICC profile itself is pretty basic. It doesn't in itself contain any information about the machine state. However, it is only accurate for that machine state. To whatever degree the machine state is ever altered in any way, that profile becomes inaccurate.

So, in specific answer to your question: While I'm not familiar with the RIP you're using, the basic answer is that yes, in just about any ICC profiling scenario. you do have to use some sort of calibration routine to establish a neutral tone curve before proceeding on to an ICC profile. So, while the calibration is not a part of the ICC profile itself, the ICC profile is only completely valid for that particular machine printing using that particular calibration.

Mike Adams
Correct Color

 

[Correct Color]

Dot Gain Curves are generally for the press. An ICC Profile is to force the proofing system to replicate the printed piece(s) once calibrated.

Not exactly.

An ICC profile is a characterization of any device that creates color using primary colors producing color in a particular state.

For the profiling scenario you're describing to work, you'd first have to be using a profiled proofer printing in a particular state, and using that profile as the destination profile for your proofer. And if that profile was not accurate, then your proof would also not be accurate.

You'd then send your file to the proofer. Depending on the situation, you could send the file in the destination color space (the printer ICC profile) or you could use the destination color space as an emulation profile. But in all cases, for accurate color, there must be a destination color space (the ICC profile of any given device reproducing color in some given state.)

That could be some stock profile like Gracol or SWOP, or, as in the case of just about any large format inkjet application, a custom profile, but it always has to be something, and it is that ICC profile that tells the RIP what dots to produce for each pixel in the file.

Mike Adams
Correct Color

 

[Asures]

Not exactly.

An ICC profile is a characterization of any device that creates color using primary colors producing color in a particular state.

For the profiling scenario you're describing to work, you'd first have to be using a profiled proofer printing in a particular state, and using that profile as the destination profile for your proofer. And if that profile was not accurate, then your proof would also not be accurate.

You'd then send your file to the proofer. Depending on the situation, you could send the file in the destination color space (the printer ICC profile) or you could use the destination color space as an emulation profile. But in all cases, for accurate color, there must be a destination color space (the ICC profile of any given device reproducing color in some given state.)

That could be some stock profile like Gracol or SWOP, or, as in the case of just about any large format inkjet application, a custom profile, but it always has to be something, and it is that ICC profile that tells the RIP what dots to produce for each pixel in the file.

Mike Adams
Correct Color

Perhaps I should have been more specific, ICC profiles are geared more towards digital devices (proofing, wide-format, or even a color printer). You don't create Press Dot Gain curves in either the Offset or Flexo world with an ICC Profile and only an ICC.

 

[Correct Color]

Perhaps I should have been more specific, ICC profiles are geared more towards digital devices (proofing, wide-format, or even a color printer). You don't create Press Dot Gain curves in either the Offset or Flexo world with an ICC Profile and only an ICC.

Okay, but...

You don't create dot gain curves with an ICC profile in any environment. There is no part of an ICC profile that does that. An ICC profile is -- again -- simply a characterization of how any device that reproduces color using primary colors does that reproduction in any given state. The whole ICC profile process isn't "geared" towards any color reproduction device or process in particular.

The term "dot gain" got its origin in the litho world long ago, and I'll agree that a lot of people in the purely digital world may give you a blank look if you use that term. But creating a neutral tone curve by whatever method and in whatever form is dot gain compensation, whether anyone realizes that or not. And in any and every event, tone curves --by whatever means created -- are part of the machine state an ICC profile characterizes; they are not part of the ICC profile itself.


Mike

 

[Asures]

Your statement is 100% accurate.