Tips for exporting to Adobe Illustrator format (AI) so CYMK colors are maintained

By Michael Law, Esri Product Engineer

Color Selector showing the menu that is shown be black triangle button.

For many GIS users and cartographers, the use of external graphics software is a common step in his or her workflow and production of print quality maps. One of ArcMap’s more popular export formats is the Adobe Illustrator (AI) export because of its wide compatibility with a number of graphics software packages. This export format was first made available in ArcGIS 8.1 Service Pack 1 and has been popular ever since. The ArcMap AI exporter has been fully tested to work in Adobe Illustrator CS and CS2. It is currently being tested in CS3 with good initial results.

Since the majority of print production workflows rely on using four process colors (cyan, magenta, yellow and black – CMYK), it is important to set them up correctly. Setting the proper color values in ArcMap will help minimize the amount of time needed to adjust color values in AI or any other graphics software. There are several basic tips in ArcMap that will help you set the correct color values for export:

  1. The colors of symbols must be set to CMYK in order to preserve those values in the exported AI file. In ArcMap’s user interface, there is no way to know whether a color is a CMYK color. Follow these steps to change it:
    1. Right-click on a color in the table of contents, or in the Symbol Selector window, click on the color chip to open the quick select color palette and choose More Colors.
    2. In the Color Selector window, click the black triangle button and choose CMYK Sliders. (Note: even if the CMYK sliders show up by default, this does not indicate the color model; the sliders that show will be the last sliders you used; they do not indicate the color model.)
      Color Selector showing the menu that is shown be black triangle button
    3. Adjust the layer color to your liking by using the sliders or enter the individual CMYK values. IMPORTANT: You must change something, even if you just switch a value and then switch it back in order to convert the color to CMYK. If you only switch the model, the internal property of the color will not get set to CMYK and the CMYK values you saw may not be preserved (rounding errors and the like are often observed).
      The CMYK dialog
    4. Press OK and Apply to finish.
  2. To export your map:
    1. From the File menu, choose Export Map
    2. In the Options area, click on the Format tab
    3. Set the Destination Colorspace to CMYK. If you have set the CMYK values for your colors, those values will now be preserved in the output AI file.
      Part of the Export dialog showing the destination colorspace option.
  3. ArcMap’s default colors (the ones initially shown in the quick select color palette) are stored in esri.style and are defined as RGB colors. When you add data and get randomly assigned colors, those colors are in the HSV (Hue, Saturation, Value) color model. These HSV colors can be converted to CMYK colors by using Steps 1.1 – 1.4 above. However, the same workflow will not change those colors to any other color model, so for instance, you cannot convert an HSV color to RGB. The HSV values will be converted to RGB and stored when you click OK. To guarantee a change in color model, choose Advanced Selection from the Color Selector’s menu on the black triangle button; then choose the model, set the values, and click OK in both dialogs.
  4. A vector layer that you have tagged with CMYK values will not preserve its CMYK values in the output AI file if a transparency is applied to it. This occurs because vector layers with a transparency are rendered as rasters in ArcMap (hence only RGB values are preserved). A workaround for this is to export your vector layer with no transparency (0%) and then adjust the transparency in AI or other graphics software. This will also improve image quality as there are no vector lines that were pixilated during the export. (Below the image on the top shows what can happen if ArcMap transparency is used, while the image on the bottom is the result of setting the transparency in the graphics software rather than ArcMap.)
    Example of transparent vectors that have been converted to raster on Export.
    Example of transparent vectors in which the transparency was set after Exporting from ArcMap.

Hopefully these tips will help you when exporting your ArcMap documents for further work in graphics software.

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12 Comments

  1. bplewe says:

    Something I just learned: it is not a good idea to specify CMYK values in ArcMap with all four non-zero. They will export to Illustrator/PDF/etc. fine, but due to a problem with the internal ArcMap CMYK-RGB conversion formulas, they will display and print far too dark or even solid black.

    The best workaround I have found is to use the formulas at http://www.easyrgb.com/math.php
    to convert the CMYK values to CMY. It’s not a perfect match, but it is very close and I get consistent results in both ArcMap and Illustrator.

    You could also use the same formulas to convert them back to XXK (that is, CMYK with one of the colors set to 0), but I don’t get quite as good a match due to rounding errors.

    The only problem with these formulas is that they assume that C, M, and Y contribute equally to grey, which they do not; but unless you are trying to do near-greys, they are okay.

  2. Trotamundos says:

    Hi!

    Remark: When speaking to “The HSV values will be converted to RGB and stored when you click OK” in the blog above, do you mean “The HSV values will be converted to CMYK and stored when you click OK”instead?

    Anyway, there is a setting I’d like to understand better when you export to AI. It is possible to set the resolution in dpi? Why? Because AI is a vector format? Is it only for the raster included in the map? Thanks

  3. cfrye says:

    If you converting the HSV colors to CMYK, that will work, but we do not support converting them to any other model.

    The resolution you define (as dpi) for a vector export will determine a virtual grid that all vector vertices and raster pixels will be snapped to. Raster export resolution is further controlled by the Output Image Quality setting, which determines the true output resolution of each raster image as a ratio of the full export resolution.

  4. billt43 says:

    Has anything changed in ArcMap 10?

  5. testy says:

    With the exception of some bug fixes in recent versions for the color picker itself, nothing with respect to AI export has changed at version 10.

    Here’s a link to the “What’s new in ArcGIS 10″ document (web help):
    http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/A_quick_tour_of_what_s_new_in_ArcGIS_10/00qp0000000p000000/

  6. MLF says:

    I’d like to note here that if your layers are grouped in Arc, then upon export to AI, symbols will be embedded with your images. This means you will be unable to rotate individual symbols, as they will be part of your hillshade/background/picture. However, if you ungroup in Arc, the resultant AI file will have logical groupings based on each layer, and you will have the control you need over the symbols.

  7. mattlove says:

    followed the instructions in the blog above, however when I set the destination color space to RGB the resulting export (AI) has the correct colors. When setting the destination color space for the export file to CMYK, the colors are modified considerably. The colors seem to be washed out with gray. I do not understand this. Could you provide a more thorough explanation of what is going on here. I can’t seem to find good documentation in ESRI manuals. Thanks.

  8. mattlove says:

    My workflow is building colored shaded relief in ArcMap and Photoshop. When I export the CMYK raster as a tiff to be imported in photoshop, my instructions are to check the export data boxes for “Use renderer” and “Force RGB”. Is this converting my colors to RGB during the export and [erhaps why I’m getting the results posted above?

  9. cfrye says:

    Yes–using Force RGB when exporting a raster (via the right-click on the raster layer -> data -> export option) will cause differences when the colors used to define the layer were set as native CMYK colors. Because this post was originally written over four years ago I suggest you contact technical support to verify that there is not a more reliable way given that we have introduced at least one major new version of software as well.

  10. mattlove says:

    It is an old post but as recent as 5/11/2011 this post is still being referenced by ESRI for related questions. For eaxmple Technical Article 33778, “Is it possible to preserve CMYK colors when exporting to Adobe Illustrator (*.AI) format?”.

  11. mattlove says:

    Does anyone have a solution to this? The recommendation does not appear to apply in Arc10, or at least I haven’t figured it out. All colors seem to be maintained in RGB regardless of following the steps above, even when custom colors are defined and saved as CMYK in styles. Unfortunately I do not have access to technical support through the non-profit license I’m using.

    • abuckley says:

      Most likely your colors look washed out because you are converting to CMYK. CMYK doesn’t have the same gamut (i.e., range of colors that can be defined), so some colors that are super bright and saturated in RGB are going to look toned down.

      Side note: We are not quite sure what you are asking in your last comment. If you are seeing RGB then you are not defining the colors correctly and you might need someone to help you…for this contact Esri Technical Support at http://support.esri.com/en. Also, we are not sure what recommendation you are referring to.