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I have a bunch of work in ArchiCAD that contains colored backgrounds and black linework. Exporting this to a color PDF results in RGB separations.

  1. Is there a way for ArchiCAD to export designs to PDF in CMYK, rather than RGB?
  2. Supposing it's not possible, is there a way to "repair" a RGB-exported PDF so that I can get K:100 black for the linework? (Ideally, something semi-automated, so I don't have to redo all the work with every update to the design)
  3. Have you had success with importing DWG / DXF files in Illustrator? I have never been able to import one, but maybe I'm doing something wrong.

(This is going to an offset print job and the design will be vulnerable to plate misregistration with the lines being present on all four CMYK plates)

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    I would normally use PitStop Pro to fix things like that. It's a plug-in for Adobe Acrobat which provides many ways of doing global changes (it's quite expensive). But it might be possible to open your exported pdfs in Illustrator and fix the colors there. If it's vector that is. – Wolff May 12 at 10:23
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    In Illustrator you can change all occurrences of a color in one go. There are several ways. For example select an object, choose Select > Same > Fill Color/Stroke Color and choose a color. Or try with Edit > Edit Colors > Recolor Artwork... (this isn't really an answer since I suspect that there is an easier way - you can't be the first ArchiCAD user with this problem) – Wolff May 12 at 10:48
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    And another tip: Make sure that the black lines overprint or you will also have misregistration issues. – Wolff May 12 at 10:51
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    @Wolff I was going on the Select Same route, because somehow the existence of Recolor Artwork eluded me all this time. Thank you! This sounds like a reasonable approach, and I'll study it more to see if I can save it as a repeatable action or something to that effect. – Dan Burzo May 12 at 10:52
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    Archicad has no cmyk support – joojaa May 12 at 11:05
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I can add a few thoughts, as the ArchiCAD-to-Illustrator workflow is one I spent a long time perfecting both for on-screen [RGB] and print [CMYK] output, with a need to match specific paint chips, brick tones, and occasionally Pantone chip colours - note colour key at bottom right of image.

Illustrator coloured elevations from ArchiCAD

Some more of my ArchiCAD-Illustrator example images


Read point (1) through carefully please - it's critical to your question.


1) ArchiCAD (as Joojaa has correctly commented) has no intrinsic CMYK support, however you can define the specifics of a given pen colour in the pen tables to whatever you need, and there can be dozens of pensets in an ArchiCAD file, so you can specify one to a given RGB that you already know has a decent CMYK conversion, or at least one you've typified with your output device. This means you can have pensets in ArchiCAD which are effectively colour palettes aimed for use on a particular device, in the same way you output graphic design with a specific colour profile embedded for the target device it you're working at that level of control. Thus, even though ArchiCAD has no intrinsic CMYK support, it functionally doesn't matter if you take the time to typify your best conversions. There are pre-made GDL objects which output the entire penset as a colour grid on a test sheet, which will help you do your conversion testing.

Remember, originally, ArchiCAD pensets were matched to the specific pens of output plotters, back when large-format output was using literal pen-based plotters - you can use pensets as a major power-tool to help you manage print output differentiated between many different devices with care and time invested.

2) As Wolff pointed out so correctly in their comment, Illustrator's Select Same tool makes bulk colour conversions so simple and easy that you don't really need a lot more than that.

3) ArchiCAD DWGs will work fine in Illustrator, as will DXFs, but they will be just as segmented as the PDF linework, and cannot carry colour or greyscale properties well, and so cannot, for example, bring shadows in elevations, whereas the PDFs can.

4) In my personal ArchiCAD-to-Illustrator pipeline, I output from ArchiCAD via PDF, as I get best scale control that way, and can carry colour and greyscale info without trouble. I typically bring the PDF in, explode it, and work with the native elements inside Illustrator. I use the Select Same to choose elements with the same line colour, and move all linework to its own layer for ease of use, and bring that layer to the top of the draw order. I collect all shadows, put them on a layer, turn them all hard black, and then put a transparency on that whole layer of 33% and multiply, then put it second from the top in the draw order. All other elements, fill patterns (which have lower lineweights) colour fields, entourage, I draw or select and move to their own respective layers for ease of management - and name each layer clearly in plain English - not using CADD abbreviations. When next this Illustrator file is worked with, in weeks or months or years, it might be the intern using it, or the marketing director - or you, after so much time that your conventions have changed - so be clear!


You have a crucial early workflow choice - you can open the PDF in Illustrator and thus then edit native elements, or you can place and link it in; if you do link, you cannot, for example, change colour models of the underlying info, as you can't edit the linked info at all. One thing to bear in mind is that you can start linked, and later if more in-Illustrator control is needed, embed and explode.

When you do decide for a given project that you want to keep it linked to allow for design iterations, you draw your areas of colour and shade natively in illustrator, and you don't export those from ArchiCAD (Layers and Graphic Override settings) and you then place the linked PDF linework at the top of the draw order - it's great for iterating (as long as no-one changes the ArchiCAD sheet, or the view on the sheet at all - so have the BIM Manager lock those) as each time the design changes, the PDF is published as part of the milestone publishing process, you open in Illustrator and can instantly see what needs alterations, as now your colour blocks and shadows are misaligned with the linework. It's a great workflow for early design iteration, but can be limiting once you want to make specific graphic or æsthetic tweaks in the Illustrator file which you can't do in ArchiCAD - line texture / brushes, stroke weight dynamics - at that point if the design is not iterating as much or as quickly, it make be time to embed and explode the linework.

Hope this helps.

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    Thank you for the detailed answer, it's exactly what I was looking for! – Dan Burzo May 15 at 17:00
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I thought I'd post the alternative approach, using Recolor artwork after working through @Wolff and @GerardFalla's suggestions, which have helped a lot!

Just to reiterate, in my particular case I'm looking at preparing a RGB PDF exported from ArchiCAD for CMYK offset printing, as to minimize the potential issues from plate misalignment. To that end, we're looking at:

  1. Making blacks and greyscales only use the K channel
  2. Overprinting the linework

Step 1: Mapping the RGB colors to CMYK

Caveat: on the one hand, the Recolor Artwork... looks like it might be a more ergonomic alternative to Select Same. However, it's one of the more confusing UIs in Illustrator and I have not been able to find official documentation on what everything in the dialog does.

  1. Open the PDF in Illustrator and change its color space to CMYK by using File → Document Color Mode → CMYK.
  2. Select all objects (⌘A) and proceed to Edit → Edit Colors → Recolor Artwork…

In the dialog:

  1. Color Reduction Options…, deselect Preserve: Black to be able to map the rich black to K:100 black [there must be a reason why this is not the default?]
  2. Switch the color picker to use CMYK sliders;
  3. Select each color in the list, one by one, and adjust it to the preferred CMYK values. In particular, make sure blacks and grayscales only use the K channel.

Step 2: Overprinting the linework

With the content still selected, go to Edit → Edit Colors → Overprint Black… and hit OK.

(Alternatively, you could trap the linework instead of overprinting it, but in my case I think overprinting matches my intention more closely.)

Step 3: Check the C/M/Y/K separations

Use the Window → Separations Preview and toggle the C/M/Y/K plates on and off to ensure everything looks as expected.

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    I also find Recolor Artwork pretty confusing, so I've never really dived all the way in. That's why I didn't feel like posting an answer :-). Just wondering... Is it really necessary to touch other colors than black? I mean, if you like the colors as they are you could just keep the colors as RGB, fix the black colors and then convert to the correct CMYK profile on export to pdf? – Wolff May 15 at 17:22
  • You're right: you'd mostly be touching the black / grayscale colors. I guess you could reduce very similar colors to the same value as part of this process too. – Dan Burzo May 15 at 19:06

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