Question: what is the difference between pgbk and bk cartridges?
Answer: What's the difference between PGBK and BK? PGBK ink is intended for uses like text, it's smudge resistant and good for fine lines. BK ink is intended for photographs, it's richer. ... So, you can force a Canon printer to use BK ink instead of PGBK by telling it that you are printing a photo onto plain paper.