Issue

Even with the use of a monochrome/grayscale plot style table in the 'PDF.dwg', the generated PDF files contain colored lines.


Cause

This problem can arise, when the AutoCAD drawing contains lines that have non-'Index Colors' assigned to them. Only 'Index Colors' are mapped to a Black/White value in the 'monochrome.ctb' and ''Grayscale.ctb" plot style tables. To check if a line is 'True Color' or 'Index Color' you can select the line and check the format or name of the color:

In this example a 'True Color' was used, that is not mapped in the mentioned plot style tables. 'True Color' colors are displayed in the RGB format whereas 'Index colors' are displayed as one number or a name. For example 'Red' and '173' are Index colors.

True color example


You can go to 'More colors' to open the 'Select Color' dialog to see all 'Index Colors' there:

AutoCAD dialog for selecting a color


Solution

To resolve this problem, an 'Index Color' has to be assigned to all lines in the drawing so that they are mapped properly to a monochrom/grayscale color.


See also