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AI won't flatten artwork or merge layers

Mar 29, 2010 7:38 PM

I am working with AI CS 11.0.0 on a Mac G4 OS 10.4.11


I designed a poster made up of several photos, each with a drop shadow, and layered upon one another. I want to flatten it all and make a PDF in preparation for printing.


When I go to the Layers pallette and choose Flatten Artwork, nothing happens. nothing changes. The separate layers remain the same.


Also, in the Layers pallette, Merge Selected is grey and unusable. What could be going wrong? Why can't I flatten this poster?



  • Currently Being Moderated
    Mar 29, 2010 8:04 PM   in reply to mpkadobe

    They are rastered images so you might have to go to Object>Flatten Transparency and choose 100% Raster you might then have to also after it is flattened select all the pieces and go back to Object>Rasterize.


    Or come to think of it you might be able to select all of the images with drop shadow and simply go to Object Rasterize.

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    Mar 30, 2010 3:27 AM   in reply to Wade_Zimmerman

    No need to flatten in your Illustrator file, just save a 1.3 pdf, this wil be flattend.

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    Mar 30, 2010 9:02 AM   in reply to CHMprepress

    Or better yet, choose the PDFX-1a from the Standards dropdown in the PDF Save dialog. This will flatten everything and will be ready for printing.

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    Apr 10, 2010 7:01 AM   in reply to mpkadobe



    You are trying to think of Illustrator (object-based, vector) in Photoshop (single raster image) terms. Two ENTIRELY different worlds.


    You don't "flatten" things in Illustrator in the sense that you do in Photoshop. Nor should you want to. Doing that would rasterize the entire file. You are misunderstanding the meanings of every one of the commands you referenced.


    68MB is not a large file for a full-page ad in a commercial offset printing workflow. (But I suspect your raster images are grossly oversampled.)


    Best practice when designing for full-color offset printing is to work in CMYK, but that's not to say there is anything technically "wrong" with including RGB elements; you're just effectively deciding to "trust" whatever inevitable automatic conversions from RGB to CMYK that most definitely will occur somewhere along the printing workflow.


    Frankly (and I do not mean this as insulting, so don't take it that way) if you don't understand the difference between Illustrator and Photoshop any better than this, you really shouldn't be using it for cost-risk work.


    From where you are right now, best advice is simply to save the file as a press-ready PDF. The resulting PDF will self-contain all the raster and vector elements. The rasterization ("flattening") of overlapping raster effects will be automatically generated by default settings. If the resulting PDF is 68MB, don't worry about it. If your printer is worried about that, find another printer.


    If this is going on press, do a proof before committing to film and plates, and/or have someone who knows what they're doing check it over.


    This stuff isn't rocket science, and I don't mean to imply that. But you can get yourself into cost trouble if you don't understand the process.



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    Apr 11, 2010 6:28 AM   in reply to mpkadobe
    ...I am designing an 18" x 24" poster....


    The first question for anything intended for print is: How will it be printed? (Offset sheetfed press? Offset web press? One-off large-format printer (glorified inkjet printer)?)


    I suppose I could edit them to be 300dpi at the size they will be printed at.


    The second question for anything intended for conventional halftone printing (as opposed to stochastic screening, commonly used in large-format inkjets) is: What halftone screen ruling will be used? That is what determines the appropriate PPI for your raster content.


    If I were building the design shown, this is how I would do it. For discussion purposes, I'll assume sheetfed offset, conventional CMYK halftoning, 120 LPI:


    1. Open each image in Photoshop, convert it to CMYK, perform any needed color-correction.

    2. Open the large background image in Photoshop, at its full original resolution.

    3. Crop (to a size including bleed) and resample the background image to 180 PPI (1.5 * the halftone ruling).

    4. Import, crop, scale, position the smaller images on additional Photoshop Layers.

    5. Individually sharpen each Layer appropriately.

    6. Apply the drop shadows as Layer Styles in Photoshop.

    7. Flatten the whole raster composition to a single Photoshop Layer. Save as TIFF.

    8. Import the TIFF into Illustrator.

    9. Add the vector elements (including holding lines of the small images, if any.)

    10. Save the AI file. Also save as press-ready PDF, without AI editability.

    11. Open the PDF in Acrobat Pro, check everything with the Preflight toolset. (Ex: in your example, one common error to check for is accidental overprinting of white text.)


    The resulting file is as simple as can be. Vector objects are vector, as they should be. No automated "flattening" of raster effects will be required downstream, because there's only one raster image, and no live raster effects are applied in Illustrator. This is slightly more work than just willy-nilly application of live raster effects in Illustrator which many designers are prone to do nowadays; but it avoids any possibility of nasty surprises such as stitching artifacts that can wreck a print job.



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    Apr 11, 2010 11:19 AM   in reply to JETalmage-71mYin

    Two friendly amendments, both a matter of habit and choice more than correctness:


    1. I do all Photoshop editing in RGB mode. Pixel clean-up, color- and luminance-correction, cropping, sharpening. There are more filters available in RGB mode, I find channel manipulations simpler, and I believe after over a decade working in the program that the post-corrections conversion to CMYK is infinitely more precise and faithful than years ago. After the conversion I'll deepen the black channel and be done with the images.


    2. As the press-ready PDF job options will flatten your artwork, I'm not as fussy about placing a flattened image file in Illustrator as I used to be. The layered PSD image preserves last-minute change options. As for TIFF vs. PSD, while both are robust and reliable, I've not found any special advantages in the TIFF format nor any threats to health in the PSD format.

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    Apr 11, 2010 11:40 AM   in reply to Doug Katz
    I do all Photoshop editing in RGB mode.


    I don't follow any such global rule about in which mode to perform "all" editing.. There are color corrections possible in CMYK not possible in RGB and vice-versa. Same goes for LAB. But that opens a discussion beyond the scope of this thread.



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