Having color management turned on or not in preferences doesn’t make any difference whatsoever. It should always be turned on (otherwise your color is random, and your results will be too).
Whether you choose to embed a profile when printing — THAT makes a difference (and is supposed to!).
And it’s up to you to decide whether you get better results letting the RIP do the color conversions or doing them yourself in Photoshop.
Whether you choose to embed a profile when printing — THAT makes a difference (and is supposed to!).
What if a file is in CMYK, does it matter whether you embed the CMYK profile used during conversion in PS or not when saving?
Chris
Thanks for the answer. By not embedding the profile for a file in photoshop and not embedding it is pagemaker, my problem went away.
Eco – Yes, of course, because the image can be in a CMYK colorspace other than that of your printer.
Chris,
That is if I am proofing my CMYK file into an inkjet printer, right? But If my CMYK file will now be output to imagesetter or platesetter, does the embedded profile still relevant? I asked this because I believe that on this instance, embedded profile is not relevant anymore. For the reason that the profile will not affect the separations because the file was already in CMYK which I believe variables such as dot gain, inks, methods, etc. (that are basically what inside a CMYK profile) were already applied during the CMYK conversion in PS. Am I right in my understanding?
Thanks.
Eco
Eco,
the CMYK is made for the final offset process – therefore embedding of a profile is not only useless but also confusing.
Proofing requires a RIP which accepts a source profile (this is the offset profile) and a destination profile (this is the inkjet profile).
It´s absolutely sufficient to TELL the RIP which profiles are used. Embedding would cause an enormous overhead.
(Based on proofing by Best Colorproof).
Best regards –Gernot Hoffmann
"does the embedded profile still relevant?"
That completely depends on how the RIP is configured and what settings are used.
You can tell the RIP to either honor or ignore the embedded profile.
Eco – the first statement still holds.
Your document could have a profile for EuroStandard, but be doing to a SWOP press – in which case it will look wrong unless you embed the profile or convert it yourself.
And unless you include a profile, the receiver won’t know how the document is supposed to look.
And unless you include a profile, the receiver won’t know how the document is supposed to look
Ah, good point. Thanks.
Your document could have a profile for EuroStandard, but be doing to a SWOP press – in which case it will look wrong unless you embed the profile or convert it yourself.
I guess it will still look wrong even if I embedded my CMYK profile. I have never met a Prepress Operator who cares to tell that my file will undergo conversion again because it doesn’t match their press specifications. And even if there is, I will not let him touch my CMYK file nor his RIP to internally convert back my CMYK file to composite RGB and back to CMYK. Sharpening an image is a not an easy task and I will not let anybody ruin that. Thus, it will still look wrong.
The best thing to me to do is to take back the job and convert the original RGB file for SWOP specifications then send it again to press.
And unless you include a profile, the receiver won’t know how the document is supposed to look.
Yes. I agree. My point Chris is that assuming that I am a service bureau, then a client walk in and ask me to output his PSD CMYK file into negatives. So I open his file in PS which has no embedded profile and I ask my client, "Sir, your file has no embedded profile, I do not know what it’s gonna look like?" And the client answered, "Don’t worry I already have a proof of what it’s gonna look like, all I need are the four negative plates." So I send it to my imagesetter. Question: Are the CMYK plates will be different if the file has its CMYK profile embedded?
That completely depends on how the RIP is configured and what settings are used.
No. I believe it does not depends on that. I am talking about CMYK document going to platesetter or imagesetter.
You can tell the RIP to either honor or ignore the embedded profile.
Again, I am talking about CMYK document going to platesetter or imagesetter. You cannot tell the RIP to either honor or ignore the embedded profile. What you can tell or not tell the RIP is to apply a given ICC profile (separations profile) everytime an RGB information came in. And even if you have RGB document, you cannot embed a CMYK profile to it. Color Separations have only two ways: (1) Do it with your front-end workstation (ex. PS) which is usually the case, or: (2) Let the RIP do the dirty work and the RIP will give you the option to either honor or not the RGB’s embedded color space but you have to tell to the RIP what is your target separations value, be it ICC or manually enter the values you wanted. So I came to a conclusion that embedded profile in a CMYK document has no bearing when RIPpping to platesetter or imagesetter which I need to be validated, thus my question to Chris.
the CMYK is made for the final offset process – therefore embedding of a profile is not only useless but also confusing.
Indeed. See above. And thank you.
You dont have to convert from CMYK to RGB and back to CMYK. Just convert to profile.
"You cannot tell the RIP to either honor or ignore the embedded profile."
OK, apparently not on whatever RIP you or your printer is using.
Converting RGB to Euroscale and printing by the real process SWOP is a very bad idea and I hope that nobody recommends this really.
The conversion between two CMYK profiles goes through CIELab and causes FURTHER losses.
The only exception is proofing. The gamut of a quality inkjet is very large, for Mutoh 6100 approximately like Adobe RGB(98). This gamuts contains with some restrictions at Cyan any offset process.
The objection, without embedding the offset profile one doesn´t know how the doc should look is obsolete.
a) The customer had chosen the offset profile according to the Print&Pressman´s advice. The latter has simply to use this profile for the preview.
b) For the imposition a crude preview is sufficient – any offset profile.
Embedding the huge CMYK profile in each IMAGE is nonsensical – it´s anyway the same for the whole job.
If the Print&Pressman wants to proof then he knows also BOTH profiles in advance.
Best regards –Gernot Hoffmann
You dont have to convert from CMYK to RGB and back to CMYK. Just convert to profile.
You can only do that in PS but not in the RIP. And besides, convert to profile when it comes to CMYK profile to another CMYK profile, PS internally (hides) conversion from CMYK to RGB to CMYK as I understand it. Otherwise, there will be no changes at all in the CMYK plate and therefore useless.
OK, apparently not on whatever RIP you or your printer is using.
For a CMYK file with embedded profile for platesetting or imagesetting, I believe there is no RIP in the market that has feature like that because it has no use. Why should I honor the embedded profile of CMYK file when in fact it is already in CMYK? I undestand what Chris is saying and RIP can do that– you embed a CMYK profile say Eurostandard, but it goes to SWOP press–the easiest way is to tell the RIP honor the embedded profile, then convert cmyk to RGB by assigning color space say sRGB, then convert that RGB file to CMYK either by assigning the SWOP profile or entering the values of that SWOP manually in the RIP separations setup. This in-RIP conversion is for me not a good idea because of some possible degradations. One possible problem: Watch out for the shift of CMYK value of RED.
Gernot,
Again, thank you. My thoughts in CMYK to RGB should be CMYK to CIELab. I guess the same is happening in PS convert to profile when it terms to two CMYK.
And now, I can really say with straight face that with CMYK images, one doesn’t need to embed its profile as long as he knows what he is doing.
"PS internally (hides) conversion from CMYK to RGB to CMYK as I understand it."
Photoshop actually converts from CMYK to LAB to CMYK. If you did the CMYK>RGB>CMYK conversion, you are really doing a CMYK>LAB>RGB>LAB>CMYK conversion, as I understand it.
"I believe there is no RIP in the market that has feature like that because it has no use. Why should I honor the embedded profile of CMYK file when in fact it is already in CMYK?"
I’m using three different RIP systems that have this feature. RIP’s CM needs a source CMYK profile, it can either get it from the file if it’s there, or the RIP can use it’s own profile. It’s JUST and option. Some workflows benefit from it, some dont. Dont use it if you dont want to.
Jason,
Me too is using three different RIPs: Eagle RIP (level 3), Harlequin RIP (level 3) and Agfa Taipan 1.1 (level 2). The first two are tied with a workflow and has no device output plug-ins, and the last was used for outputting negatives. I learned to operate all these by just reading its manual and of course googling. And the questions that I rise about the CMYK file with embedded profile is really confusing me before about its effects on the CMYK plates. I think now I understand it. So, thank you for the inputs. And yes, I can’t find any option like that in our RIP except for incoming composite document (RGB) and CMYK to composite to CMYK option.
Eco,
"And now, I can really say with straight face that with CMYK images, one doesn’t need to embed its profile as long as he
knows what he is doing".
That´s my opinion too.
The options: choose "Source Profile" and "Destination Profile" are available in large format RIPs,
here PosterShop Pro and Best Colorproof . Both can be used for proofing, provided the inkjet has a large gamut.
The source profiles are a choice of available RGB, available CMYK or Lab, equal or different for raster images and vector graphics.
In my understanding a RIP for printing separations doesn´t need these options.
Best regards –Gernot Hoffmann
Hmm, I havent used a Harlequin in about 6 months, but I could have sworn it did have the option.
I wasnt using CM with the Harlequin though so I could be mistaken.
Anyways my general point was in response to your first question of whether or not an embedded profile will affect the color: My answer was simply – it depends on what RIP is being used and how it’s configured. But yes – it could affect the color.
I’m not saying embedding is neccesarily a good idea – some of our profiles are 4-5mb in size, so adding that to every file is silly.
I heard about (not really cheap) software that does the CMYK to CMYK conversion direct, without going to Lab and back like PS. It could help, when an image was separated to a different print process than used. But that the separation does not "fit" to the process can not be perceived until there is an embedded profile, which tells what process it was separated for. So I think it’s usefuljust as a sticker which says "separated for SWOP". So the SWOP operator can realize, that the image fits, and the EuroScale operator is warned. Although the profile is obviously not needed for any conversion things.
Eco – RIPs can do profile conversions, and commonly do. But they can also flag problem files and alert the operator (this is also a common preflight function) and give you a chance to correct mistakes.
I really don’t know where you’re getting your information, because a lot of it is just plain wrong.
The options: choose "Source Profile" and "Destination Profile" are available in large format RIPs…
Same with my Eagle RIP and with Harlequin: "intended press" and "actual press". I think there are lots of misunderstanding the way I construct my thoughts, and sorry for that. I think, Jason I got what you mean. If I am going to turn on the Use ICC profile in my Eagle RIP, I will have an option to choose my Source Profile and Destination profile and I do not know if under those option there will be such "read or retain or honor embedded profile" coz for some reason that I do not know, that option is greyed out and cannot be activated which gives me the impression that maybe that option is not available for color separations and could be activated only if I will used my Eagle RIP for Color proofing. For Harlequin, I simply do not used any of the selections under "intended press" and "actual press" and yes, I can’t find any option/selection there to use CMYK embedded profile. Maybe since I choose "none" on both options, Harlequin reads the CMYK embedded profile (I repeat maybe). The AGfa Taipan receives the PostScript files generated from both RIP.
But again, I am talking about sending a CMYK document with or without embedded profile going to my RIP to my imagesetter. I want to know if a CMYK image with embedded profile will have a difference versus a CMYK image without an embedded profile on plates then on the finished products. The embedded profile (our press profile) was used in both CMYK image, the only difference was one had embedded it to the CMYK image when sent to RIP.
And Jason, you said yes? That really confuse me. Gernot and I have the same understanding about that.
Eco – RIPs can do profile conversions, and commonly do. But they can also flag problem files and alert the operator (this is also a common preflight function) and give you a chance to correct mistakes.
Yes, I know. And as I said, I do not preferred it. Problems will be truely seen upon proofing it again as I understand after profile to profile conversion. Not like when done on the front-end application.
I really don’t know where you’re getting your information, because a lot of it is just plain wrong.
You should not be surprised about that. I am a self-taught artist and prepress technician. I’ll be glad if you are going to correct them. One of the mistake I stated was about the RGB image that can’t have a CMYK embedded profile. Yes, RGB images can have a CMYK embedded profile depending on the file formats and applications used.
Please feel free to correct me, I need those to learn. Also, I am glad that even if I cannot convey my thoughts clearly, Gernot understood what I mean.
