Fine tuning the Pre-Press feature in Acrobat. [Gray scale]

Hi WarrenR - Can I assume that you mean to say that you are trying to Convert PDF files that contain Color images and color objects as well as greyscale images and greyscale objects to a PDF file that is 100% Grayscale ?

And if this is the case - the method you are trying to use if to open the PDF file, then, under the Advanced menu selecting - well, this is where i am not clear on what you have described - I have Acrobat 9 - and there is no "Pre-press" item to select under the Advanced - there is a "Print Production" item though, and here there are several tools that might be useful to accomplish what you are trying to do.

I would use the "Convert Colors" item - and select "preserve" in the Convert Command - and also be sure to change the profile to Gamma 1.8 - what is probably happening is that the method you are using is applying some ICC profile - and this is modifying the densities.

Hope this gives you some ideas about where to look.

If you are using the "

Thank you for your advice:
We have had trouble using the method you have described in that it has also reduced the percentage of the blacks from 100% to 90% in the conversion.

Perhaps we are using this conversion incorrectly.

Sorry for the miss communication re/the location of the process I have been using.

The location of the conversion process I am using is under:
Preflight/PDF fixups/Convert to grayscale

The use of this scripted tool has saved us a lot of frustration in that it is allowing us to retain the 100% Black of our line art, but we are still getting the an increase in the percentage of the grays, of approximately 5%.

Grays will increase in percentage: from 5% to 8%, from 25% to 31%, from 50% to 55%,; but the higher percentages maintain their density 75% was fine as well as 100% Black.

You can use Callas pdfToolbox (they make most of the preflight functions) to map colors so that absolute values (in certain circumstances) can be preserved. I'd have to see your PDF to come up with the right fixes.