tiger pencil drawing-progress

i have now completed the second ear and some of the 'white' areas of the tigers face,using layers of graphite from H grade right through to 2B in some areas adding shadow tone and fur details.before completing the last white fur area i want to add tone to the neck and body of the cat so that the white area will stand out a little and i can work out the final tones for that area.To that end ive layed down a base layer of H grade pencil and am slowly working my way down the drawing.