Grayscale PDF

Converting a PDF to grayscale removes all color information and replaces it with shades of gray, which is exactly what you want before printing a document in black and white — it prevents colored elements from printing as odd, unpredictable gray tones and generally produces a cleaner, more professional black-and-white result.

Grayscale PDFs are also typically smaller in file size than their colored originals, since color image data takes up more space than grayscale data. This creates a new file — your original colored PDF is never altered.