Blackening Text, Lines and Fills

Sometimes PDF output from an application (for instance, a web browser) has text in colors which would not print well on a grayscale printer. The -blacktext operation blackens all text on the given pages so it will be readable when printed.

This will not work on text which has been converted to outlines, nor on text which is part of a form.

The -blacklines operation blackens all lines on the given pages.

The -blackfills operation blackens all fills on the given pages.