Question: how to make a pdf print in black and white on mac?
Answer: Press Command-P to print your document.
Use the PDF menu and select “Open PDF in Preview”
Choose “Export…” from the File menu.
Ensure “PDF” is used as the output format.
Choose either “Gray Tone” (for grayscale) or “Black & White” from the Quartz Filter menu.
Save the document to your Desktop.