The use of tones here gives the work some texture and I believe is used to good effect. I see in most places the color of the tone complements it's surroundings, except for the arm holding the book which has 3 red tone spots overlapping it which is a bit distracting from the rest of the piece in my opinion. Also, I like the change in line color when it's facing the light which provides great contrast and helps to see depth. Overall love it.