A second kind of correction is as follows: Ink the stone with firm color, wash it well with plenty of pure water and let it dry. Now redraw the lost places with crayon. Printing crayon work is the most difficult of all lithography, but can be done perfectly if all necessary precautions are taken. These are mainly: (_a_) proper dampening of the paper; (_b_) perfect dampening of the stone;--too much meaning that the fine points will not take color well, too little making the stone smut easily; (_c_) good stretching of the leather, industrious lubrication, and an underlay of taffeta; (_d_) a good, finely mixed inking-color that will not shade off in printing and yet does not contain too much lampblack; (_e_) soft and well-dried ink-rollers; (_f_) proper tension of the press; (_g_) utmost possible speed in printing. The latter aids enormously, because the stone does not get so much time to dry out. Aside from the spreading and running-together of the darker parts, one of the commonest faults of crayon work is that it is very liable to get a tone, which spreads over the whole design like a veil; or that the designs lose their firmness and appear "monotonic" because the shadings spread and thicken. The first fault comes from weak etching or from oil that was rancid when it was used to prepare the varnish. The latter fault makes the color adhere and smut the stone. The same fault is developed if the printing-color contains soap, which some printers mix into it for better adherence. It can occur also if the stone has lost its preparation owing to frequent cleansing and strong rubbing with a dry rag that is inky. Even strong rubbing with clean water can cause it if the rag contains fats. As to the "monotonic" effect, it is frequent, and I have learned that it can be caused in two ways, namely, if the color is squashed continually during the print, which makes the stone sooty; or if the color spreads, as, for instance, during the night or during the noonday rest. The stone is prepared only on the surface. In the pen style, all lines are prepared on the sides also, so that they cannot spread because they are considerably more elevated than the crayon designs. If a crayon design dries after printing and is not coated properly with gum, the color is liable to spread away from the design and give the plate the before-mentioned tone. Even if it is coated with gum, the color will spread, at least in the inner parts of the stone; and as soon as the very thin surface has been at all wiped away by rough usage, the underlying fattiness will appear gradually, and begin to take color.