Marbles are generally imitated with oil colours, and those colours are mostly opaque, as for this purpose it is not at all necessary that they be transparent. The manner of proceeding with the different marbles will not be detailed, but a few general instructions applicable to all of them will be given. The tools for imitating marble are less varied than those for imitating wood. A palette and palette knife, with numerous small sized hog-hair brushes and camel-hair pencils, and a duster, or worn badger-hair softener, are all that is necessary for imitating any of the marbles. The ground is to be chosen of that colour which is most predominant in the marble to be imitated; for example, in black and gold marble, the ground is black; in veined, it is white; in sienna, it is cream colour; and in dove marble, the ground is of a dark pearl colour. In proceeding to the imitation, the necessary colours are to be taken on the palette, and mixed up to match the tints in the marble to be imitated. In mixing, they must be slightly tempered with oil, and further tempered with turpentine for use; and they should not be laid on thicker than is necessary to produce the proper effect. The softer shades are first to be put in, blending the different colours, as may be, in the marble.
As soon as they are put in a proper form, they are to be softened by brushing lightly over with a clean duster, or old badger-hair softener; but in some marbles there requires to be no softening: of course, when the shades or veins are sharp and hard, they must not be softened. The softer veins may be next put in, while the soft shades or ground-work is yet wet. As soon as this ground-work is dry, the shades may be heightened, and the strong and sharp veins put in. In putting in the soft shades or ground-work, care must be taken not to mix the colours together, so as to give the work a muddy appearance; and the colours should be used as thin as will make the work sufficiently solid, or it will look uneven when varnished.