14 Replies Latest reply on May 17, 2012 10:52 PM by emil emil

    RGB CMYK preview

    gradientmush Level 1

      I've been doing some reading and realised dring print CMYK kinda dulls my stuff and wanted an all out solution for it. Either I work in CMYK completely or I work in RGB and then make adjustments to the file after converting it to CMYK which is tedious. Or I could use the pantone swatches to get to the closest I want. Also have my monitor calibrated. Instead of all this I figured if i can see the CMYK colorpsace while working in RGB it'd help a lot.  What is the recommended method to see a CMYK equivalent of an artwork while working in RGB colorspace?

      Im not sure if this means anything here but in RGB mode, I came across soemthing in illustrator > view> proof setup > Working CMYK: US web Coated, this is what I see while I'm working in RGB. does this mean anything here?

        • 1. Re: RGB CMYK preview
          JETalmage Level 6

          Frankly, it's a bad idea. You really should not even strive to work in RGB when designing for print.


          RGB to CMYK is not a straightforward, unambiguous conversion. You are essentially substituting four values for three. Simple math suggests there is a practically infinite number of algorithms for making that kind of "conversion."


          Far better to come to grips with CMYK, so that you understand what's going on, what the limitations and advavtages are--and thereby stay in control.


          Your mention of using Pantone libraries as if doing so somehow "improves" RGB to CMYK conversion suggests you don't yet really grasp spot versus process color--a whole other issue also critical to designing for print.


          Working comfortably and predictably in CMYK is not rocket science and is nothing to feel intimidated by. And it's not something to try to avoid.



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          • 2. Re: RGB CMYK preview
            emil emil Level 4

            If you have a calibrated and profiled monitor and also the color profile of the printer working in a RGB color space should give you the best possible conversion to the color space of the printer and you can also soft proof it during the creation.

            Based on my experience, I'm not able to do a noticeably different job with picking CMYK colors by working only in the CMYK color space than what color management does by converting from colors picked in an RGB color space. The colors do get dull naturally because in most cases the CMYK color spaces are narrower and can't have the saturated colors of the wider RGB color spaces. Working in CMYK from start to end simply avoids the surprise feeling when seeing the converted colors with less saturation but this doesn't mean that the converted RGB to CMYK colors will be less saturated from those picked when working in the CMYK color space. I think people who believe that picking colors in CMYK color space gives more choice than using RGB colors and then convert is simply an illusion.


            U.S. Web Coated (SWOP) v2, color space displays your artwork in the color space of commercial offset press that is calibrated to this standard. So, you should use it when you intend to print on such printing press. If you are going to use other printer you should have its color profile installed in your system and it will appear in the Customize submenu of the Proof Setup menu and you can use it to soft proof (display) the colors in the printer's color space.


            In anyway, if you want to rely on your monitor it should be calibrated and profiled with a color measuring device. Otherwise you have to rely on a lucky shot, or you can use the final printed output as a reference of the colors used in your artwork and not what your monitor displays.


            edit: didn't see the Jet's message before writing mine, and would like to say that in that regard although we have different experiences they are both valid depending on the work and workflow used. I would also choose to work in CMYK color space if I have to use CMYK values with known output.

            • 3. Re: RGB CMYK preview
              gradientmush Level 1

              the reason i mentioned pantone was because that is pretty much the CMYK equivalent or so i read and many places recommend that if you want precise colors to that of what RGB has, even then it would have some shortcomings but it's still better than just a usual RGB -> CYMK conversion.


              But I was just hoping for a CMYK preview as Im working in RGB colorspace.

              • 4. Re: RGB CMYK preview
                gradientmush Level 1

                thanks, ok so i have to ask my printhouse for their standard and if i have that installed in illustrator as my proof setup,  things would be easier is what you're saying, which is nifty.


                As for calibrating the monitor, what is a good tool for it? my IPS monitor is an Asus  PA246Q ProArt

                • 5. Re: RGB CMYK preview
                  emil emil Level 4

                  A lot of Pantone colors are outside of the CMYK color space and can be much better represented on screen in a wider RGB color space. That is is practical if you don't choose colors from the book but referring to your monitor and then sue the RGB value to find the closest Pantone match. If you work in CMYK color space this will limit the Pantone ink choice considerably to the narrower CMYK gamut.

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                  • 6. Re: RGB CMYK preview
                    gradientmush Level 1

                    ah okay.

                    • 7. Re: RGB CMYK preview
                      Jesseham Level 4

                      Pantone does sell process guides but typically when people speak of Pantone, they are referring to their spot colors, which in some cases are just as unreproduceable in CMYK as RGB bright green.


                      3rd in the pile-on:  By designing in RGB when you know the end result will be used only for CMYK, you are risking an end result that doesn't match you or your client's expectations. Here's a nice chart showing the CMYK, RGB and Pantone gamuts overlapped so you can see just how much smaller the CMYK gamut is.  By not working within the constraints of the medium you're working in, you're really leaving a lot up to fate.

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                      • 8. Re: RGB CMYK preview
                        emil emil Level 4

                        I'm not familiar with your monitor but monitors with H-IPS panels are considered as the best for color critical work. I use Spyder 3 colorimeter with Color Eyes Display pro calibration software because I have a wide gamut monitor and at the time when i got it this combination had good reviews for my monitor but that was more than an year ago and I don't know what is currently available. If your monitor is not wide gamut you have much more choices, just look it up and pick something with good reviews.

                        • 9. Re: RGB CMYK preview
                          gradientmush Level 1

                          thats it spyder! i was recommeded spyder. yeah my monitor is factory calibrated but i just want to make sure thats all. Thats what I was looking for spyder, forgot about it, thanks.oh btw the caloibration tool will be used for my old monitor, not sure why I mentioned the Asus Proart. the IPS moinitor i have is factory calibrated.the issues Im seeing with the CMYK vs RGB is more prominent in the old monitor. I havent tried it with my Asus yet, im guessing it's going to be 90% acurate atleast.

                          • 10. Re: RGB CMYK preview
                            JETalmage Level 6

                            ...print CMYK kinda dulls my stuff...

                            Of course it does. Reflective inks simply don't glow. There's nothing your software settings--automatic or manual--can do about that.


                            ...and wanted an all out solution for it.

                            There is none. Arranging dots of process standard inks is not going to match every color--let alone the luminance--of glowing monitor pixels. So stop looking for an "all out solution."


                            You can't make house paint look like artists' watercolor, either. So you work in the medium you are designing for.


                            The "kinda dull" display of CMYK working spaces in graphics apps is designed precisely to not display the bright colors that simply cannot be reproduced in process ink.


                            Working properly in CMYK, that's what you want--especially if you are one who wants to trust what you see on your monitor as anything remotely resembling what you will get in ink (a dubious proposition at any rate).


                            But I was just hoping for a CMYK preview as Im working in RGB colorspace.

                            Well, think about it: That's really what you're doing when you set your document to CMYK. Setting your document to CMYK does not magically make your monitor able to display CMYK dots. Your monitor is always displaying RGB. Always. No matter what color settings you are using. When you set your document to CMYK, you're telling the software to limit the display to something more similar to the color set that is actually renderable in process inks--which is, in effect, exactly what you are asking for.


                            But, you say, you want to "work in RGB colorspace." Well, with your document set to CMYK, there's nothing preventing you from using RGB sliders as you define Swatches. It's bad practice, but you can do it if you really want to trust your CMYK values to some under-the-table RGB-to-CMYK automatic conversion algorithm.


                            People fret way too much over this stuff. Just get yourself familiar with CMYK ink-on-paper. Then you'll know, for example, that if you really want the "reddest red" on press, you just aren't going to get anything "redder" than 100M 100Y. You can do that on a grayscale monitor, with perfectly predictable results. But try defining your colors as RGB, then convert it to CMYK at print time, and see how realiably 100M 100Y is the automatic conversion you get. Actually try this little exercise and you'll find out that putting too much trust in automatic color mode conversions can easily make your printed results more dull instead of less.


                            So don't endeavor to avoid thinking in CMYK. It's how it's done.


                            Pick up a magazine and find a photo that displays a really strikingly brilliant blue sky. Then consider: Cyan is the poorest of CMYK inks. It simply can't even come close to simulating a bright blue sky. So how does that happen in print? It happens because the guy who adjusted that image was thinking alot more about color correction than mere color calibration. And he was thinking CMYK.



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                            • 11. Re: RGB CMYK preview
                              JETalmage Level 6

                              ...the reason i mentioned pantone was because that is pretty much the CMYK equivalent...

                              Pantone is the CMYK equivalent to what?


                              ...typically when people speak of Pantone, they are referring to their spot colors, which in some cases are just as unreproduceable in CMYK as RGB bright green.


                              Correct. Pantone is a company. It publishes its own commercial standard for mixing inks, thereby giving the industry a method of achieving reasonable consistency between printers in different locations. It's all about consistency (read "calibration"), not about somehow magically making one color model more able to reproduce an out-of-gamut color of a different color model.


                              (Then there's the whole matter of fact that offset spot inks are most often far more opaque than CMYK process inks. You can anguish and spend all you want over tweaking the most minute bit of more calibrated "accuracy" out of your monitor, and Illustrator will still be country miles away from simulating that hugely impactful difference. It's a perfect example of what dear ol' Aunt Molly always called "straining at a gnat to swallow an elephant.")


                              Yes, one of the kinds of references Pantone publishes is its recommended CMYK values for simulating its spot ink colors. But spot inks exist largely because there are colors that can be manufactured from pigments that cannot be accurately reproduced by mixing the standardized CMYK process inks.


                              Again, it's about calibration, not magically-empowered "conversion." Example: It is not at all unusual for a designer to:


                              1. Specify a particular spot ink from a Pantone spot reference as the primary spec for a logo color.

                              2. Look at and consider Pantone's printed swatchbook of its recommended CMYK simulation for that spot ink.

                              3. Look at a printed PostScript CMYK swatchbook (or even make a value judgement based on experience) and decide that a different CMYK simulation is better or more technically advantageous--and sometimes even a closer simulation.

                              4. Specify the better values as the CMYK logo specification instead of the Pantone recommendation.


                              There is no law that just because you want to simulate (which is all CMYK can do in most instances) a Pantone-specified spot ink in CMYK you must therefore strictly abide by Pantone's particular recommendation for that simulation.



                              • 12. Re: RGB CMYK preview
                                DocPixel-BMW Level 2

                                @JET - just wanna say that your above post(s) were SPOT ON!!!! Perfect! I have to explain this stuff daily as well, and dare I say you did it in a couple of paragraphs far better than I need a half an hour for


                                TIP 1: any defined color within Illustrator, be it RGB or CMYK can be later edited to be a "spot color" and seperate onto it's own plate/space.


                                TIP 2: you "can" edit Pantone colors to your viewing needs. Change "Book Color" to process, and be sure to give them a new name, like "Pantone 100C_DP" (my initials).


                                TIP 3: get a printed CMYK grid book; then match calibrated printed/proofs of your design to both the CMYK book (to see that 100m-110y for ex. is printed that way just to be safe) and later spec to the closest Pantone swatch.


                                In my main business of packaging design, we have to print spots and CMYK on many different types of paper, board, etc. and simulate them when doing the design comps and presentations. This means that we have to create our own CMYK mixes at design/proof time, and later label them and convert them to PMS spot colors for production. Been doing it like this for 20+ years.


                                NOTE: if you want super-tricky, try simulating at design/presentation time, 2-3 spot color tints overprinting each other... many times a picture... without expensive software like that from Esko(!)

                                • 13. Re: RGB CMYK preview
                                  gradientmush Level 1

                                  thanks a lot Jet, that was a long brief explnation that cleared up a few things.

                                  • 14. Re: RGB CMYK preview
                                    emil emil Level 4

                                    As someone said in another thread about working with color, it doesn't matter which way it is done, as long it is done right.

                                    If I know the printer and the paper, and that's the only way the artwork will be used and printed, I will do it in CMYK and have  full control of the values.

                                    If there is a lot of variables like using different printers and media presenting different color spaces with different gamut, I will choose to create the artwork in the color space with the widest gamut and then convert from there to the other color spaces using the color management conversions.

                                    If the destination is unknown I will create it in a wider RGB color space.


                                    The approach also depends a lot on the artwork. if it is a simple graphic with a number of manageable colors that can be recreated for each destination color space with reasonable amount of effort then I would just recolor.

                                    And It also depends on the priorities, and the goal when dealing with different outputs. The same CMYK values will produce different color appearance on different printers, If the goal is to match the appearance of the image on different printers as close as possible, then I would use color management conversions. But if the goal is say, to produce the most saturated colors each printer can produce then I would use the same CMYK primary values for each printer even though this will become tricky with the midtone values because the same values won't guarantee the maximum saturation in each color space.


                                    The monitor color accuracy of simulating color spaces becomes crucial when creating artwork for multiple destinations and having the color profiles of the different  printers is a must.


                                    Just another 2 cents from me