Pottery decoration under the glaze

by M. Louise McLaughlin

CARVING IN CLAY.

This work can be made very beautiful and effective by those familiar with the use of carving tools. The tools used should be short-handled carving tools, and the ware should be in the “green” state and as for incised work, neither too wet nor too dry. Dry enough for clean cutting with the tools, and yet not so dry as to be brittle. When in just the right state, clay forms a fine substance for carving. As it dries very rapidly, means should be used to keep it sufficiently moist until the work is finished.

The outline can be drawn upon the clay with a sharp-pointed modeling tool, and the carving can be executed with gouges, chisels, and parting tools of the various shapes and sizes necessary. Veining can be done with a pointed modeling tool, and dots can be readily incised by pressure on the surface. Raised dots can be made with softer clay which has been dipped up in a quill of the required size, which is then pressed upon the surface at the place where the dot is desired.

Carved work can be finished by the use of sand paper, a camel’s hair brush, and water, or a sponge; but these should not be used very freely, as they will injure the sharpness and cleanness of the cutting, which it is desirable to preserve. Carving looks best when finished with a “smear” glaze.

Another variety of carved work can be produced upon a vase which has been previously dipped in colored “slip.” The design is then cut through the covering to the ground beneath, which should be of a contrasting color.

Another method by which many varied and beautiful effects can be produced is that of incising lines, and cutting or pressing designs into the soft clay, which are then filled with various colored slips. The lines or other designs should be deeply cut, moistened with water and filled with the colored clays, which should be pressed into the depressions and allowed to dry. When dry, the surface can be scraped in a similar manner to that made use of in finishing incised work. It should be noted that in this latter work the body of the clay should be in a softer state than would be necessary for other carved or incised work.

Carving in clay, as well as modeling and incising can be glazed with the colored majolica glazes with excellent effect.

CHAPTER VII.
PAINTING UPON THE BISCUIT.

After the ware has been fired once and is in what is called the “biscuit,” it can be decorated by the use of underglaze colors, in the form of thin washes resembling water-color painting. Ware used for this purpose should be made of white, or very light cream-colored clay, as the colors, being used in transparent washes, would be dimmed, and would have their tints sullied by use upon a ground of dark color.

On white ware those colors should be used which will best stand the heat necessary in the firing and glazing of this ware. For this reason painting executed on white is usually in monochrome, and only the strongest colors are used, such as blue, black, or brown. The best effect is produced by the use of blue. This style of work is familiar from the numerous pieces of Japanese ware, of porcelain or white earthen-ware, painted in blue, which are brought to this country.

The method of painting is simple and not likely to prove difficult or uncertain as to its results in the hands of one familiar with the use of water colors. The color generally used is dark blue, and there are several different blues which furnish very fine tints. Among these might be mentioned Emery’s cobalt blue, which is excellent and does very well upon the white ware manufactured here. Phillips’ mazarine blue and Harrison’s Persian blue are also very rich, deep colors, the latter having a purplish tint. One of the best blues, as reliable and pleasing in color as any, has been prepared by Mr. Joseph Bailey, of the Hamilton Road Pottery.

The color must be rubbed down until perfectly smooth, and should be mixed with water and enough gum arabic to keep it from rubbing off in the necessary handling before firing. The design having been sketched upon the ware to be decorated, with a lead pencil, the first washes may be put in with a light tint of the blue. These should be laid on with a free hand and without retouching before they have dried. The darker tints may then be laid in, and lastly the deepest shadows. These should be painted thickly and sharply to give the proper depth of color. If necessary they may be painted over a second time; care should be taken, however, not to have an excess of paint in any part, as that would prevent the glaze from adhering to the ware. The lines should be particularly clear and sharp, as they generally spread more or less in the glazing, and if they are not well defined and the shadows are not dark enough, the effect will be blurred and indistinct. In this kind of work clearness and distinctness are to be desired. If the painting is carefully executed and the various degrees of light and shade are well preserved, something of the effect of a painting in water colors will be produced. Monochromes in brown and black are done in the same way, only that in the case of the latter color it is better to mix a very little blue with it, as that will make it stand the fire better. Before glazing, the ware should be fired once to “harden on” the colors. If the color should run in the glazing, the painting may be repaired by the use of gilding over the glaze, by which the blurred outlines may be concealed. When, from the perfection of the firing, this is unnecessary, work of this kind, and especially that in blue, may be very much enhanced by a judicious use of gilding.