To produce the stump effect, rub the chamois block in the box of crayon sauce, and then with the large grey paper stump commence by putting in the darkest parts and the cast shadow. Use the broad end of the stump, moving it over the surface of the paper with an even and uniform pressure, so that you will not make any dark spots. Make broad lines and have them cross each other so as to form diamond shaped spaces, using considerable care and a very light touch in the lighter places. Finish with the large rubber eraser, cutting it so that it will make white lines about the same width as the black lines made with the stump. Have these light lines run into the dark ones in some places, and use the rubber so as to produce a dashing effect.