Printer Profile CMYK vs RGB

[MonsterBabyBLN]

im new here and just started to build my first CMYK profile for an old EFI designer RIP for my Z3100.

i used the built in linearization and then printed the ECI2002 CMYK and read it once with my DTP20 and then with the built in i1 as well.

the ICC profile i got thru profile maker is way smaller then my RGB profile for the same paper and settings.. and smaller then the profile from EFI as well..

do u have an idea what i could have done wrong? thnx

[Lukas Engqvist]

Very hard to say. Were the print heads clean and you are using a proofing paper? Are you using standard inks? (alternative brands may give you larger or smaller gamut) Are you printing high quality? (Many rips and printers have several quality /speed variables) Some papers have smaller gamuts, so it is not necessary to assume something went "wrong", it may be right. Also what RGB are you comparing to? sRGB, AdobeRGB or ProPhotoRGB?

[MonsterBabyBLN]

hmm.. well of course i am comparing the RGB profile for the paper with the CMYK profile for the paper ..;-)
i dont think this has anything to do with s A or photoRGB ...

and i am using the original inks of course. and always did. and the printheads are clean. linearilazed.. and high quality..

and of course i am talking about the same paper.. for both profiles.. it is HP professional proofing paper.. but again.. that cant be the point..

any other idea?

[Correct Color]

Creating CMYK profiles is an art. What you do is create the state of the machine, then characterize the machine in that state. And it's the creating the state of the machine that's the issue.

In setting your single-channel ink limits, then linearizing the machine and then setting your multi-channel ink limits, you'll determine the gamut of color your machine will be capable of reproducing once you characterize it in with an ICC profile.

Of course all that has to go on somewhere. When you don't use a RIP and print to a machine such as that one as an RGB printer, all the state-of-the-machine settings, as well as black generation and the like, are handled by the 'black box.'

The size of your CMYK gamut versus the size of the gamut you get from the machine as an RGB printer tells you--most likely--that the state of the machine in the black box is a good deal better than the one you made in the RIP.

(Edited to add: There's also the possibility that you printed your patches incorrectly. If you inadvertently applied color management to them somehow or another that could cause a small gamut profile as well.)

Mike Adams
Correct Color

[MonsterBabyBLN]

mike.. that answer doesnt help me.. but you are absolutely right ;-)

and if i wasnt asked for some contract proof prints.. i would have always stayed with qimage!..

but now i am a lot smarter.. well more educated... it was really fun!

and we are always talking about those ink limits.. and i understand that this is more important than i thought.. because my efi designer rip software has no chance to linearilize the channels..
i thought the built in linearilization (cant write that word anymore!) would do.. as this printer and program was state of the art only 4 years ago..
but.. it only gets me close to detlaE 2.6 in the wegde.. and i dont think i can tune it more ;-)

[michaelejahn]

the ICC profile i got thru profile maker is way smaller then my RGB profile for the same paper and settings.. and smaller then the profile from EFI as well..

do u have an idea what i could have done wrong? thnx

Depending on settings and software - some profiles can be much larger (or smaller) than other profiles.

When building a profile, we have the ability to use more data points in the profile for better quality and that is why the profiles we create are so large.

Depending on how complex the device is to model, the profile may be anything from 1K to several MB in size.

You can see the data in the profile by opening it in a profile inspection utility such as Profile Inspector.

ICC Profile Inspector

hope this helps.

[MonsterBabyBLN]

interesting link thank you!..

but back to the question..

i am talking about the same paper, the same hardware, the same printer, the same spectro, the same software..

once used to define a RGB profile.. and once for a CMYK..

so i dont understand your answer.

"When building a profile, we have the ability to use more data points in the profile for better quality "

why do YOU have the ability to use more data than me ??

[Correct Color]

I was assuming you meant gamut size, and he was assuming you meant file size.

[TerryWyse]

i used the built in linearization and then printed the ECI2002 CMYK and read it once with my DTP20 and then with the built in i1 as well.

the ICC profile i got thru profile maker is way smaller then my RGB profile for the same paper and settings.. and smaller then the profile from EFI as well..

do u have an idea what i could have done wrong? thnx

Sounds to me like you may have had color management enabled somewhere in the pipeline....so while you thought you may have been profiling the printer at it's full gamut, it may have been restricted by a source/destination profile along the way.

Also, how are you dealing with the extra inks in the z3100? Profiling this printer as RGB via the HP driver, they deal with the extra inks behind the scene. With CMYK (or CMYK+OG), there's usually a special process in the RIP for dealing with the extra inks.

Regards,
Terry

[MonsterBabyBLN]

thanks terry.

through the last days i ve gotten a lot smarter about this whole process.

i def. did not have CM turned on as i was printing the targets thru my RIP.. efi designer. which is some years old.. so there is the point.

it cannot do inklimitation or multi channels. its kinda built for this printer tho.
and uses a whats called cantone engine that splits the cmyks.. to the 12 inks...

i know this is not state of the art. but it was only 4 years ago. and was supposed to get accurate proofs.. maybe now as easy and quick as today.. but it is supposed to work.

so i am trying to figure that out before investing in new software.. if my hardware is good enough..

back to the question.. im pretty sure i found out the answer myself thru the days.

yes.. if u can not limit the inks per channels.. you will get a smaller gammut because in the shadows there is just too much ink..

could that be it ?