Color to gray convertion

[rande]

With acro 9.4 and pitstop pro.
What is the best way to convert to grayscale making the black 100%
I've tried many things. Maybe there isn't a way but thought I would ask.
thanks
Rande

[dabob]

you should be able to replace all of the RGB black with 100% K using the global change pallet in pitstop

[mattbeals]

These are unequal proportions of RGB and the blacks are not solid 0,0,0 so it would be a bit tricky. What did you import into Quark?

You could use the select similar tool to select all fills of the same color. Global change would also do it. But as it is you've got 13.73, 12.16, 12.53 RGB. So even if you did convert it to gray you're gong to get a screen. So you should select similar and change the fill color to 0 device gray or 100 K.

[Stephen Marsh]

If the source files can be fixed so that all elements are 100K, that would of course be best. Then the PDF would be correct from the get-go...

If one only has Adobe apps and no other Acrobat plugs, then I would use one of two "hacks" to get the job done. If you have to many of these jobs, it would be of course best to get the job done correctly up front.

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OPTION 1 (Don't crucify me, I know all the general warnings against doing this!):

In Acrobat, go to Doc props and the fonts tab and write down the fonts used. Load said fonts. Open the PDF into Illustrator, replace fonts as needed with local versions and recolour vector elements to be 100K. Placed images may need to be extracted and fixed in Photoshop, then re-linked in Illustrator.

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OPTION 2:

Convert a dupe of the original PDF into grayscale mode in Acrobat. Place the PDF into InDesign. Copy/Paste in Place the PDF over the top of itself. Select Colour Burn as the blending mode of the top dupe. Export out a new PDF. Convert to grayscale in Acrobat if needed (preserve black and or preserve cmyk primaries option on). This of course means that the PDF will have transparency used, which would need flattening in the file or at print in a PostScript workflow.

An example of this "Colour Burn Blend" hack is attached.


Best,

Stephen Marsh

[Lukas Engqvist]

With acrobat there is a convert to greyscale preflight action wich works great.
Can be saved as a droplet.

You could also use the colour converter which will do a good job if you accept to change all to black and white. But your black is not even pure black, I'm getting 14-15% R G and B. Funny it says ICC based device colour talk about contradictory information.

Why are you exporting rgb data from quark anyway?

[mattbeals]

I think it may be a PDF placed into Quark and Quark is again fracking up.

[m0m0]

hi rande

have a look at this conversion. is this what you had in mind? so far i only found one way to achieve the 100% K conversion you are after since the source file is quite funky in its appearance.

tool used is part of heidelbergs prinect pdf toolbox - color editor