Converting Color PDFs to Greyscale or Black and White

It’s rare to find color printers or copiers widely deployed in law firms. When color documents appear in discovery, firms don’t always know what to do with them. Examples include PPT files, images scanned in full color, etc.

Acrobat files can contain color and non-color elements:

RGB: Red, Green, Blue color
CMYK: Cyan, Yellow, Magenta and Black
Greyscale: Shades of gray ranging from 0 (white) to to 256 (black) in value
Monochrome: Black and White

RGB or CMYK image-only PDFs, in particular, can be quite large. Converting these PDFs to grayscale or black can reduce the size of the file and speed printing.

Other times, litigation support departments will have to satisfy the odd attorney who prefers to read greyscale documents.

Whatever the reason, it is fairly easy to convert RGB or CMYK PDFs to Greyscale. It’s a bit more difficult to convert to monochrome, but I’ve included a workaround for that, too. You’ll need Acrobat Pro to make this work for you . . .

Converting PDFs from Color to Greyscale

To convert an RGB PDF to Grayscale:

Open an RGB PDF.
Choose Tools–> Print Production
Select Device:RGB Convert as the document source color space.
Select Gray Gamma 1.8 or 2.2. You may need to experiment to see which gives you the best results.
Select Do Not Embed Profile from Conversion Options.
Click OK

Converting to Monochrome

Unfortunately, Acrobat cannot convert documents to monochrome directly. The workaround is to convert to monochrome TIFF and then re-convert to Acrobat.

This process works well for image-only color PDFs. PDF Normal documents– containing vector fonts and text– will no longer be searchable unless OCR is performed after conversion.

To convert a PDF to Monochrome TIFF

Choose File Save As
Choose TIFF from the pop-up menu at the bottom of the window.
Click the Options button.
Set as below:

You can convert back to PDF by opening the file in Acrobat. If you have a lot to re-convert, you can use Batch Processing in Acrobat Professional.