The little finger and ring finger on the left hand look awfully stiff. Trying to duplicate that pose with my own hand, it's a really unnatural pose, but makes sense if the hand is stretching around in an effort to reach the sleave of the other arm like that. I think, in that case, the fingertips of those two fingers would have some backward bend from being pressed hard against the paper. Interesting problem, I think I understand that your intent is to create an Escher-type effect, in which case what you really want is a dimensional transition, 2D to 3D, that confuses the eye. I've never tried anything like that, but my guess is that you need to carry the 2D pencil outline of the arm up to the bend of the wrist, gradually transitioning the shading from a light pencil shading near the edge of the sleeve cuff, showing the paper grain, to a full skin texture at the wrist. I think your shadows ought to trasition from an obvious paper grain to realistic shadows where you want the image to appear 3D. This will be quite a trick to pull off, and my hat's off to you if you can manage it! Gromit