(SEE SPECIMEN PLATES.) The comb or nonpareil marble belongs to those edges which are not so frequently used, although it is superior in brightness and variety of colors to other marbles, provided the combination of colors is a correct one and there are no entire blotches of the same color present. For the comb-marble in general use, four colors are mostly employed, namely black, blue, yellow and red. To these white is added, but not as a color, as it is formed by the stylus in drawing the colors. For precaution's sake let me here repeat the description of the preparation of colors: before using them shake well and then pour into the different small vessels as much of the same as is necessary for one marbling operation only, then put them away handy for use in the following order, black, blue, yellow and red. Black is used for shading all other colors, therefore, it should be thrown on first as the ground color. As I mentioned before, the colors are to be prepared upon a small surface of size so that the whole size may not be soiled, as it is nearly unavoidable during the preparation to prevent several drops from sinking. Whether the colors are suitable to each other as regards their expanding power or whether the size is too thick or too thin for comb-marble is determined in the following manner; draw off the size in a dish, by a strip of paper, throw on a drop of black, which if size and color are correctly proportioned must expand to a spot of 4 inches in diameter. If the drop does not expand in this way the size is either too thick or more gall must be added to the color. Add from 5 to 10 drops of gall to the black color and repeat the experiment. If then the color does not expand to the given diameter take a stylus and draw it in wavy lines such as used for comb-marble. If the color can be drawn into beautiful straight lines, without following the stylus, the size possesses the normal consistency and more gall must be added to the color, until it reaches the aforementioned diameter, but if the color is drawn along by the stylus or cannot be easily cut by it, then the size is too thick and must be carefully diluted with water. If, on the other hand, the color in drawing with the stylus should run, then the size is too thin. This can also be easily seen by the extraordinary quivering of the size. Such a size cannot be used for comb-marble, either you must add some thick size or you must use it for common marble edges. The black color is the key to the success of a beautiful edge; the other colors must be prepared according to the strength of the black.