14 Replies Latest reply: Mar 28, 2014 9:56 AM by John McCustion RSS

    Vector RGB vs. CMYK issues

    maf79 Community Member

      I am not an advanced Illustrator user so please talk in elementary terms.

       

      I downloaded several vector files from shutterstock.com. I need to change them from RGB to CMYK. Below shows what happens when I switch the color profile. How do I keep this from happening? Image 1 is RGB. Image 2 is CMYK.

       

      I'm using Illustrator 5.1 on a PC.

       

      rgb_tree.png

       

      cmyk_tree.png

        • 1. Re: Vector RGB vs. CMYK issues
          Monika Gause CommunityMVP

          What exactly do you do? Please name the function you are suing.

           

          On top of that: since nobody here knows how that file is built, probably no one can tell exactly what is happening. The image contains some transparency and a lot of blend modes. Those operate slightly differently in CMYK mode.

          • 2. Re: Vector RGB vs. CMYK issues
            Mike Gondek2 Community Member

            With your RGB document open you should just have to use

            FIle >> Document Colro Mode >> CMYK

             

            Can you select one of the white circles and check to see what blending mode may be applied in the transparency palette.

            • 3. Re: Vector RGB vs. CMYK issues
              maf79 Community Member

              I am changing the color mode how Mike mentions above.

               

              The blending mode is color dodge.

              • 4. Re: Vector RGB vs. CMYK issues
                maf79 Community Member

                Edit: They are a combination of screen and color dodge.

                • 5. Re: Vector RGB vs. CMYK issues
                  Mathias17 Community Member

                  Simply put - blend modes yield different results in CMYK than they do in RBG, and vice versa.

                  • 6. Re: Vector RGB vs. CMYK issues
                    emil emil Community Member

                    The blending modes appear different in the different color spaces because they are not affected by color management but the biggest change is in gradients. If the artwork uses one or a few gradients just redo them in the CMYK  color space and you should be fine. For best possible match in order to use color management you have to first select all and rasterize the image at the output ppi resolution. Then when  you convert to CMYK only out of gamut colors if any, will cause change in appearance.

                    • 7. Re: Vector RGB vs. CMYK issues
                      Mathias17 Community Member

                      Yes, I was going to suggest rasterizing as well and doing a strategic conversion to CKMY, not just a simple CONVERT. DONE. NEXT . . . But rather do it carefully so as to maintain the appearance as best as possible.

                       

                      Of course, the OP image is obviously using plently of out of gamut RGB colors. The artwork will have to re-worked in order to convert to CMYK well.

                      • 8. Re: Vector RGB vs. CMYK issues
                        emil emil Community Member

                        Yes, there are some out of gamut RGB colors but they are not a problem for  the color management conversion if there is no gradients and certain blending modes. This is straight conversion from sRGB to u.s. web coated swap v2. using the raster image and it would be the same if using vector objects with flat colors. Given the narrower CMYK gamut, I think that's the best it can get in matching the original RGB.

                        Capture.JPG

                        • 9. Re: Vector RGB vs. CMYK issues
                          Mordy Golding CommunityMVP

                          Blend modes are simply ways of combining overlapping colors. CMYK and RGB use two VERY different methods for blending colors (additive vs subtractive). So the result of a screen blend mode will be different across these color models. In order to convert this artwork to CMYK, then the suggestion mentioned above -- rasterizing your artwork -- is really the only recourse you have. You can do this by choosing Object > Rasterize, and then choosing an appropriate resolution. After that, you can then convert your document to the CMYK color space.

                           

                          Mordy

                          • 10. Re: Vector RGB vs. CMYK issues
                            Jesseham Community Member

                            If you select one of the now-white circles, can you "Select -> Same -> Fill color" to pick up the rest of them?  Is it possibly solvable by switching the blending modes to something that works, or adjusting the converted color to something that works with the blending mode?

                            • 11. Re: Vector RGB vs. CMYK issues
                              emil emil Community Member

                              Yes, as I suggested earlier, if all of these circles are using the same fill and appearance, it won't be a big effort to select and change them. It is most likely the gradient of these circles that needs adjustment. The blending modes can make a difference but not such big difference as shown on the image. Probably the blending modes can remain the same but with adjusted transparency. It is the gradients that are making the big difference.

                              • 12. Re: Vector RGB vs. CMYK issues
                                Luke Jennings Community Member

                                Just out of curiosity, what happens if you go to View> Overprint preview?

                                Try opening your file in Acrobat and go to Tools> Print Production> Convert colors> Output intent (SWOP). If you are lucky, your file will be converted to CMYK without the missing parts, and will retain the vectors, although the colors will change.

                                • 13. Re: Vector RGB vs. CMYK issues
                                  maf79 Community Member

                                  overprint preview doesn't show it any differently.

                                  Here's what it looks like when I did what you suggested in Acrobat....better, but shows more white around the bottom of the tree.

                                  tree_6_12.png

                                  Rasterizing it seems to work.

                                   

                                  Some of the terminology a couple of you use I'm not sure about because I'm not advanced in Illustrator.

                                   

                                  Thanks so much for your help.

                                  • 14. Re: Vector RGB vs. CMYK issues
                                    John McCustion

                                    Late, I know, but I had a very similar problem. I really didn't want to rasterize the artwork. I finally found that when I converted my artwork to CMYK, that the "black" gradients that were used to create an opacity mask changed to a CMYK mix of black rather than 100% black. When I changed the color of the mask to 100% black, the artwork that it was masking looked exactly like it was supposed to.