A similar fault may develop with the second rubbing-in, after corrections, and from the following causes: Poor color containing sand; too much pressure with the greasy rags; the use of rags not sufficiently cleansed of any soap used in washing them; rubbing-in of color with too dry a color rag; in brief, from anything that may destroy the stone's preparation wholly or in part. Sometimes this defect may be remedied by mixing more gum into the printing-color and into the water with which the cleaning-rags are wetted. A firmer color may aid, if it is rubbed away by fairly strong pressure of the rag as soon as it has adhered. This operates as a remedy because the firm color takes hold of the dirt that has set itself into the pores of the stones, and when it is removed, takes the dirt with it. If none of these have results, there is nothing left except to grind off the plate very slightly and carefully with an exceedingly fine stone and gum solution. In the case of very delicate designs, this is not applicable, because the finest lines have practically no depth. Therefore they must be washed instead, a rag being dipped into weak aquafortis or very much diluted phosphoric acid, and passed carefully over the stone till the dirt disappears. It is well to mix in a little gum, and also to rub acid-proof ink into the stone first, that the etching fluid may not attack the design too much. After this cleansing the tone will disappear, but another fault often appears in place of it. The color, after rubbing-in, will not permit itself to be wiped away readily, because the etching has caused some roughnesses to which the color adheres in the form of little specks. A number of clean rags with gum solution must then be used, or the stone should be lightly rolled a few times with the ink-roller after being rubbed-in. The roller will take the specks. Indeed, the fault hardly ever appears if the inking-in is done with the roller, as suggested in the remarks about the third form of inking-in. As soon as some few impressions have been made, the roughness of the plate disappears gradually and it can be wiped off without leaving specks behind. Gentle rubbing with pumice finely powdered and mixed with gum solution will remove the defect in the very beginning, but care is needed lest the design be injured. (2) A line that has so little depth that it is almost level with the surface of the stone can be made as black as a deeply engraved one by continued rubbing with the color rag. In using a firmer color the lines, especially the wider ones, can be so overloaded after a while that the ink will squash under the press. This surplus can be removed again by the use of the ink-roller, but it is merely adding unnecessary work, as proper practice in inking-in and the use of exactly the right consistency of color will prevent the trouble.