How to use a classical and archival technique for transferring a “cartoon” drawing to canvas for painting without wrecking your drawing. You can just use your drawing for the transfer, but using tracing paper means that you can have more than one shot at it and retain your drawing for reference. By using raw umber instead of other materials, you are not introducing foreign materials to your painting that may have unwelcome side effects on your painting down the track.
Drawing is an easy way to work out overall proportions and a simplified lighting map before applying paint to the canvas when you are tackling a more considered and layered painting.