Turn a PDF black and white MONOTONE
Every colour is rewritten as the grey of the same lightness and every picture stored again in grey, so the text stays text. Each page is then checked for colour left.
The PDF
Drop a PDF here
or choose it
The result
Doing this often? PDF Studio checks a PDF before printing: fonts not embedded, pictures too coarse for print, and the colour setting the printer needs. On its own, US$2 a month; with everything else, US$5 a month or US$48 a year. 7 days free.