Episode 106

Episode 106 – The CMYK Episode

by heathenx

In this screencast I demonstrate how to use a couple of utilities to convert an RGB image created in Inkscape to CMYK. I used Inkscape version 0.47.

There are several applications and utilities to choose from in order to convert an RGB image to a CMYK image (Gimp w/Separate+ plugin, Scribus, and tifficc deserve mention) . In this screencast I show just two: Imagemagick and CMYKTool. For Imagemagick I have provided a text file with the commands that I used. Currently, my personal favorite is CMYKTool due to its simplicity with drag-n-drop. πŸ™‚

NOTE: I made a mistake during the screencast when I converted the CMYK TIF to CMYK PDF with Imagemagick. I included an input sRGB color profile when that was absolutely unnecessary. I think I was paying more attention to the output color profile than what I had for the rest of the command. I believe it converted just fine but it might have confused a bunch of you. Whoops! I fixed this in the provide text file.

If anyone would like to post their current workflow for CMYK (if they have one) then please do.

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83 Responses to “Episode 106”

  1. Luxman Says:

    Hello and congrats for this extremely useful and well-done screencast
    I followed your tips to enable color management on inkscape and I can properly see a simulation of the printer output (in my case profile FOGRA27) but I am stuck on the part regarding colorspace conversion. Here’s what I’ve tried:

    – export to PDF and then use imagemagick convert to create a CYMK pdf. Problem is the new PDF sucks, the resolution is very low, in a word unusable.
    – export to PNG and then convert to CYMK tiff using imagemagick. Here I got a proper resolution but I got some bluish tint that wasn’t expected simulating the same color profile with inkscape. I have to mention that I didn’t find the sRGBColorSpaceProfil.icm inside the file I downloaded from Adobe website, so I used either Adobe RGB or a profile I created for my monitor using LPROF (without a colorimeter) as pointed out here http://www.ubuntufieldmanual.com/?q=node/38
    – Importing the PNG on CYMK tool gives me an error: “Source image must match source profile!”
    I know that I can just send the RGB file to the tipography and they will take care of the conversion using some proprietary software but I would really like to achieve the same as shown in the screencast.

    Sorry for the long post.. πŸ˜›
    Thank you! πŸ™‚

  2. Lazza Says:

    You can actually tell Imagemagick which resolution to use when converting the PDF. πŸ™‚

    convert -density 288 …

    Thanks for the calibration link. I’ll try that. πŸ˜‰

  3. heathenx Says:

    @Luxman

    Well, since you are on Linux, you can try a different method. Install the gimp-plugin-registry package to install the Separate+ plugin (and a crap load of other useful plugins). Open your Inkscape project and export as a 300 dpi png. Open that png with Gimp and go to Image>Separate>Separate and then export the CMYK tiff when done. That will get you a CMYK tiff. Now go to Image>Separate>CMYK Tiff 2 PDF. Find your exported tiff, select your color profiles and export your CMYK pdf. Done!

    For you Windows users, you’ll be able to use Separate+ to export your tiff but I’m not sure the CMYK Tiff 2 PDF is available. In that case you can fall back to Imagemagick (or Scribus if you want to preserve the vector).

  4. Richard Querin Says:

    @heathenx

    Just to chime in here, I’ve used Eckhard’s CMYK TIFF 2 PDF plugin a few times on Windows XP in the past and it seemed to work fine for me.

  5. heathenx Says:

    @Richard

    Thanks! I’ll have to give that a try. πŸ™‚

  6. Luxman Says:

    Thank you for the info. I have done many tests and I came up with rather confounding results…
    Basically the three tools (convert, CMYKtool and Separate+) can give me different outputs for the same color profiles.. The most consistent result has been an image converted with convert from png to tiff (sRGB to FOGRA27) and a corresponding tiff image with a sRGB profile assigned with convert and converted to FOGRA27 with CMYKtool (which doesn’t accept as input an image without a color profile assigned in my tests…). Anyway no converted image gave me an output similar to that I could see on inkscape using the color management tools… Question is: what will the tipography output look most similar to?…
    The color management world is interesting but very difficult…

  7. heathenx Says:

    @Luxman

    I’m curious. Have you tried tifficc (for Linux and Windows)? It’s an alternative to imagemagick. It might give you another different result.

    Here’s a sample script:

    tifficc -i sRGBColorSpaceProfile.icm -o USWebCoatedSWOP.icc -t intent -c quality -b test_rgb.tiff test_cmyk.tiff

    ref. http://linux.die.net/man/1/tifficc

    By the way…I exported a png from Inkscape and converted to a tiff with Gimp for use with tifficc. πŸ˜‰

  8. Luxman Says:

    Ok, I tried tifficc and it gave identical results as imagemagick with the inkscape exported PNG file or CMYKtool with a tiff previously profiled (sRGB).
    Now the only way to find the truth is to print it… I will update you as soon as I get the results.
    It’s strange that the color preview on inkscape give me a different color output than the tiff profiled file… Moreover it’s not clear to me the function of the document property to link a color profile… Any clue?

  9. Luxman Says:

    Following my previous posts: I finally printed my artwork and _surprise_ the print is much more similar to the png file exported from inkscape than to those converted with imagemagick or cmyktool with the proper color profile (Coted FOGRA27)… However the color ICC preview on inkscape (using sRGB as display profile) gives an even better approximation of the final printed copy, and that’s really cool πŸ™‚
    By the way do you know what’s the linked color profiles option under Document properties-Color Management is for? I don’t notice any difference changing the profiles linked to it…

  10. Dirk KrΓΌger Says:

    @Lazza: I ilke your Tux Avatar, can you make a video how you made it (if done with inkscape) and send it to heathenx?

  11. Lazza Says:

    Thank you. Actually I made that by merging two Tuxes found on CrystalXP, the site of the famous Tux Gallery. The operation was done in Gimp, but you can find a PS tutorial on how to do that (yes, they draw Tux and use Ps =.=). http://www.crystalxp.net/forum/en/Graphic-Tutorials/Photoshop-Tutorials/sujet_2585_1.htm
    If you plan to replicate that in Inkscape it’s quite easy, but somebody did the job for you. πŸ˜‰ http://en.wikipedia.org/wiki/File:Tux-G2.svg

  12. jonoave Says:

    Thanks for the really useful screencast!

    I had the same problem like Luxman with the CMYK tool, so I have to go try using Imagemagick. I’m still quite new to Linux systems, so installing stuff always gives me a pause as I try to figure out what to do.

    But again, thanks for the great screencast!

  13. Darth_Gimp Says:

    Just stopping in to say I miss you guys… πŸ˜€

  14. Mateus Machado Luna Says:

    Excelent tutorial! I started doing this, but the dpi was getting smaller. Like, I had a png with 300 dpi and the tif was 118. I don’t now if that’s normal. Then I tried importing the png on Gimp and use de separate plugin to convert it to CMYK and it worked fine, preserving the 300dpi. Anyway, that’s very nice. But a question. Like you said, the green becames really vivid in the tif-cmyk. Will it became like this when I print it or it will be like in the inkscape-rgb file that i see in my screen?

    Thank you very much and please, keep working on this site, it’s just excelent!

  15. heathenx Says:

    @Mateus
    I can’t tell you with any certainty what your green will look like printed. It always take me a bit to get my head wrapped around CMYK after being away from it for a while. The last couple of takes that I had I switched over to a Scribus workflow and got some consistent and predictable results. Gimp/Separate works very well but maybe give Scribus a spin and review your results. πŸ˜‰

  16. JavierSam Says:

    Mateus:
    I do not know what your problem is, but it seems to me that you have a “units problem”. Because 300 dpi is equal to 118 dots per centimeter.
    So I guess that there is no resolution change. I don’t know, I’m just thinking aloud…

    Hope this helps. And hope my english is understandable…

  17. yun YAN Says:

    great thanks from Wuhan, China πŸ™‚
    I design my personal logo with the help of your 098 episode.

  18. Reg Says:

    Hi there:

    Thanks for a great screencast.

    I’m a novice user of Inkscape 0.48.1. It is my understanding that Ver. 0.48.1 supports CMYK inherently, because I do see a setting for CMYK within the “Fill and Stroke” menu. Is my assumption correct? If I create a .eps file and export it to .png, do both files have the necessary CMYK information within them? Or do I still need to convert them like you explain?

    Thanks.

    Reg

  19. JavierSam Says:

    Hi Reg.
    While we wait for the “real” answer of heathenx or Richard, let me tell you that Inkscape doesn’t support CMYK yet.
    The possibility of defining colors CMYK within the “Fill and Stroke” menu is a sort of fancy. It’s not real. I guess that it will be in future versions.
    For the time being you need to do what the masters says in this video.

    Greetings.

  20. Reg Says:

    Thanks for your reply JavierSam. I guess I just might have to convert all my images then. πŸ™

    Reg

  21. juli Says:

    buenos dias tus tutoriales son muy buenos y espero que como salgan las versiones nuevas pongas mas inovadores.

  22. kazak_boy Says:

    hi every body out there! i am so excited ,for i have here found this inkscape tutorial which i am searching google all the time before. this is fantasitic job! thank you !

  23. mac Says:

    Hello! That’s all we can see/learn about amazing Inkscape!? Why are you stopped publishing new episodes?

  24. heathenx Says:

    @mac

    No. That’s not all there is to learn about Inkscape. πŸ˜‰

    The Screencasters are in deep hibernation. I cannot speak for Richard but I’ve been devoting much of my time toward learning other artsy things and acquiring new skills along the way. I sometimes go from one thing to the next and time just falls away before I know it. Can’t help it really. I’m interested in everything.

    If I have time to make more screencasts then I will certainly post them. In the meantime, head over to the inkscapeforum.com and hang out with all of the other Inkscapers to get your fix.

    By the way, Richard and I are still here…we’re just quieter. You can contact us any time. We try our best to be helpful if you have questions. Just don’t ask us about women. We haven’t figured them out yet. πŸ˜‰

  25. Lazza Says:

    For the last thing, you can try running this in a terminal:
    man "understanding women"

    LOL πŸ˜€

  26. Vlad S Says:

    Very thank you heathenx and Richard!

    At last, after 3 months of watching I can write this comment:) I started learning in January 2012 and just finish. You gave me a strong basis in vector graphics. Finally I don’t afraid Inkscape with a lot of its tools.

    Very thank you – you made very valuable and selfless job for all people! Great Respect to you! Let the fortune and success accompany you, be healthy and happy every moment of your life!

    Vladyslav,
    Kyiv, Ukraine

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  29. Oliver Says:

    Hey,
    nice video tutorial,
    but you applied the RGB->CMYK-conversion twice,
    (first time: png -> tiv, and then tif -> pdf) and so I think you got wrong results.
    Also, I think, png -> pdf should also work in one step…

    Oliver

  30. heathenx Says:

    @Oliver
    i don’t believe i had gotten the wrong results (but perhaps). teach me how to do it a different way with imagemagick. i’m rather curious.

  31. irena Says:

    please help

    hi, i’m very new at this (programming not design). how do i install cmyktool. both you and the site assume i know how to do that but without an .exe file or right click which gives me an isntall option, I’m lost.
    I’ve installed colour profiles!! many thanks :))

  32. heathenx Says:

    Hello, irena

    CMYKTool can be downloaded from here: http://www.blackfiveimaging.co.uk/index.php?article=02Software%2F05CMYKTool

    Basically, you download one of the binary zip files (0.1.6-pre1), decompress and double-click on the CMYKTool.bat file to run it. However, it might throw up some errors if you don’t have some supporting .dll’s in your bin directory. I grab mine from my Gimp install. If you have trouble with that part then I can zip up my directory and email it to you.

    I haven’t used CMYKTool since about this episode. Not sure how stable it is anymore. The last few times I needed CMYK, I opened my SVG file in Scribus and exported from there.

  33. CMYK conversion using Linux | Wolkensichel Says:

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