Separating CMYK and Spot Colours

[Jack Wenlock]

Hello,

I have a PDF where I have CMYK and a Spot Colour. The Spot Colour is intended to be used for digital foil, but I need to separate the two.

I can of course select all CMYK objects and delete them using an action, but the CMYK knocks-out the spot colour when viewing in output preview. When doing it this way, there's no knockout behaviour and I'm left with a full shape rather than parts cut out of it.

Is there a way you can "simulate" printing the PDF with separations turned off so you can keep knock-out behaviour when separating the two?

For workflow reasons we'd rather have a PDF containing CMYK, and another PDF containing foil before imposition.

[loicaigon]

Can you post the file? Otherwise you can send it to me at loica (at) enfocus (dot) com

[magnussandstrom]

You can convert any separation to spot color None. Spot color None is a PDF 'special color' and should behave as if you turned off a separation in a RIP.

So if your PDF consists of CMYK + Spot color Pantone 021 C:

1. Remap each CMYK channel to spot color None = Only the spot color will be left
2. Remap Pantone 021 C to spot color None = Only CMYK will be left

This usually works with knock out and overprint objects too.

Here is two sample actions that you can edit to suite your specific case:

Actions.zip

(4.52 KiB) Downloaded 748 times

A similar topics:

viewtopic.php?p=13146&hilit=spot+color+none#p13146

viewtopic.php?t=4261

[yosimo]

...there's no knockout behaviour and I'm left with a full shape rather than parts cut out of it...

Yes, this is a known problem. The trick is that everything you want to omit the foil must also be created with 0% tone value of the foil color (and should be set to overprint in a composite workflow).

If you want to get the foil extract as a separate PDF, then it seems to me the easiest way is to color all cmyk and grayscale objects by foil color 0% (color any existing RGB and other color objects as well) and save as a new PDF.

In the original PDF you can then delete the foil color separation with a separate action list and thus obtain the print PDF.

ActionLists_yosimo.zip

(4.36 KiB) Downloaded 795 times