I agree, it sounds as if you are not developing the print for long enough. You should find out how long it takes before no more changes occur. This might be, say, 2 minutes. Then add another 30 seconds, and always develop for this length of time (say, two-and-a-half minutes).(posted 9213 days ago)If you then find that blacks and whites are still both grey, you could use a higher contrast grade of paper (or change the filters if you are using variable contrast).