Not really thrilled with these for coloring books. They did not lay down smooth and were scratch and uneven in color...  I was disappointed as I had really liked the color range.  Could be the paper in the books, but I have tried them on all sorts of paper, cardstock etc and just not good. If you are getting them for kids to use then I am sure they will be fine. I'll stick with my Bic and Sharpies and Steadtler pens