I am curious about what palette to use for what purpose. I know you are supposed to use CMYK palette when designing for separations printing processes, but on the other hand - you could use the RGB palette just as well, if you have a color calibrated system and a printer profile and if you leave a PDF to the printer, which I suppose most people do. It works if you set the color output to CMYK and use the printer ICC profile for conversion.
So, what is your choice regarding color models? It would be interesting to hear how you all work.
Hello there Shabbadang,It depends really on the assignment, and from time to time.I have different colours, my own palette of colours, so that even if I work with RGB it comes out as I like it when I cmyk it. But then of course, as long as I dont know the quality of the paper, or dont have a profile from my client or the printer (tryckeriet eller kunden), I go by instinct when colouring my illustrations I make for magazines and newspapers (Tabloid, morning newspaper or glossy magazines paper).If the client and myself set up a profile then of course I follow that specified colour profile, weather its cmyk, RGB or even PMS/Pantone.But 99% of the time I ask the client questions if necessary how they like to have it delivered. There are times, if not so often, but still, when the client ask for RGB.
Hej Stefan,
Your answer is a bit elusive ... But I try to understand it [:-)] Anyway, my question really boils down to me thinking the RGB palette is sort of easier to work with. The CMYK palette gets rahter dul when you turn color calibration (CM) on, while the RGB seem to retain a wider gamut (but that must be wrong, mustn't it?) so it's easier to find a color you like. The CMYK palette gets rather muddy, especially the darker greens, with CM turned on. So I'd rather use RGB, buth then again, you don't want to be too far off gamut.
Hi Lars,
Some follow-up info:
Thank you Jeff for your answer. However I think I know about the good stuff with color management and so. It's a bit more subtle than that. See my answer at your blog.
Posting your response to my blog here:
Lars: My wonderings about this subject really stem from the fact that If I have both the standard RGB and CMYK palettes open and I turn CM off, they look exactly the same, then with CM turned on, the CMYK palette is mure subdued than the RGB one, thus making it harder to find colors especially among the darker shades that really come to look very much the same, especially among the (cmyk) blues and greens. I don't know why this is, because I figure the CMYK colors are mapped into RGB space, so C100 is equal to G255B255, so they should, but they don't, print the same. Anyway, I'd rather use a palette that looks like the RGB one in CM mode, than the extra dull CMYK one. To me it seems like the CMYK palette is too darn dull, when CM is applied even though it varies quite a lot with the ICC profile in action. But anyway, can you tell me why C100 doesn't print like G255B255? They are the same colors uncalibrated (w/o CM on) and should be the same in a calibrated state. Shouldn't they?
Jeff: Any insight?
Lars Forslin said:If my assumption that the colors in standard palettes mathematically are the same, then they should print the same, but something makes them not to and I don't know why
Monitors don't reproduce Cyan Chromatic correctly. Printed yellows are richer than monitor yellows. RGB color space is bigger, so there are some RGB colors that can be printed. There are so many Color Managers. Many Pantone Inks can't be reproduced with CMYK. This is why you don't get what you see.
The only way to obtain good prints (100% of the time) is reading ink, and printing via PostScript. There C100M80Y0K20 (blue) will print approximately correctly.
Michael Cervantes said:Monitors don't reproduce Cyan Chromatic correctly
What's cyan chromatic? Just a fancier word for pure cyan? Anyway that doesn't answer the question why C100 and G255B255 don't print the same if they are the same colors mathematically. I have a theory: when you print to an inkjet CMYK colors are converted to RGB and then back, while RGB colors are converted just once (to CMYK). When you print to a PS device only the RGB values are converted to CMYK, and if the profile isn't good enough, there will be differences. Right? In that case I have yet to find accurate printer profiles and I suppose I must build some better ones.
Michael Cervantes said:RGB color space is bigger, so there are some RGB colors that can be printed.
I suppose you mean can't be printed. Anyway, they should print the way they're reproduced on the monitor if CM is applied an you have a correct ICC profile for the output device. Right?
Michael Cervantes said:Many Pantone Inks can't be reproduced with CMYK.
I don't use Pantone inks. Not so far at least.
Michael Cervantes said:The only way to obtain good prints (100% of the time) is reading ink, and printing via PostScript.
I don't know. My Phaser Solid ink printer is a postscript printer, but it seems to have limited color space. I suppose an inkjet has a larger gamut and therefore better. Maybe one should use a software RIP and print to the inkjet? I tried that, but it looked awful, but I probably didn't understand how to run it. Can you explain why it has to be a postscript device? I would also be happy to hear what you mean by "reading ink".
Lars Forslin said: I suppose you mean can't be printed. Anyway, they should print the way they're reproduced on the monitor if CM is applied an you have a correct ICC profile for the output device. Right?
Yes I did mean "cannot". Nope. They print approximately what is reproduced in the monitor. Monitor cannot reproduce cyan chromatic or richer yellow, so they will not print like you see them in your monitor.
Lars Forslin said:Can you explain why it has to be a postscript device? I would also be happy to hear what you mean by "reading ink".
Corel print engine doesn't perform any change in color values when the object is CMYK. If an area in your image is C100M80Y0K20, that is the value that the RIP will receive, and it is the value that should be printed. This way you know that your image will print fine, and if not, you can complain to the print shop. Ink reading is exactly that, user read the ink value in objects a area of them to be sure what color will print, and if the printing device is capable of. For example if you have an image that the darker shadow read C85M73Y73K75, and you are going to print to a device that is limited to 260 Total Ink. That shadow is not going to print fine, and the pressman will reduce the amount of ink, probably watching out text, and other areas of the image or printed page.
That is correct, the assignment of CMYK values does not change when it arrives in a RIP nor does it if you output to a .pdf. If you have Acrobat Professional and use it for prepressing your own work, you will be able to measure the values are identical. This holds true for spot color also.
My problem is the inconsistencies between RGB and CMYK models. Please see my recent note to David Milisock. I made a bit of an investigation there. I have a hard time to believe that RGB colors should be mapped into a color space that is smaller than CMYK! Instead they should be mapped into exactly that space. Thus G255B255 should be mapped to C100. Correct?
The way the colors are mapped depends on the selected rendering intent!