Pottery decoration under the glaze

by M. Louise McLaughlin

These are two of the simplest as well as most effective methods of decorating pottery. We will treat first of incised work in clay.

The piece of ware to be decorated must, of course, be in the “green” state; not too wet, yet not dry enough to be brittle. An outline drawing can then be executed upon its surface with a pointed modeling tool, not too sharp, and perfectly rounded at the point. If any burr is thrown up in the course of the lines, it must not be brushed off until the piece has become partially dry. The drawing can then be brushed over with a stiff camel’s-hair brush, leaving the lines free. These lines can now be filled with dark (under-glaze) paint (black is best), mixed with a little gum arabic and water. In going over the lines some of the paint will extend over the edges; this can be scraped off, when the clay is dry, with the edge of a sharp steel blade, two or three inches long, held between the fingers and thumb. A broken knife-blade will do for the purpose. This scraping must be very lightly and carefully done, to avoid injuring the surface of the ware. The surface may afterwards be rubbed over with the very finest sandpaper, when entirely dry.

The finish of this work must not be a full glaze, but the “smear” glaze, described in the last chapter. A full glaze would fill up the lines, and so injure the appearance of the work. In order that the black lines may be effective, the ground of the decoration should be rather light in color. The best colors for the body of wares to be decorated in this way are light cream color, or a mixture of cream color and red clay, producing a light brick-red; or, if they can be procured, any light colored clays which have been artificially tinted in the body. A colored ground for this work can be procured by having the piece of ware dipped in colored slips. The design is then incised upon the surface, after it has become dry enough, in the same manner as before. The lines are cut through to the body of the ware beneath, showing a color contrasting with that upon the surface with good effect. Work of this kind is also executed upon stoneware. That of Miss Hannah Barlow will be remembered as an instance of incised work, in black lines, upon a red or light brown body. Incised work also appears upon the Lambeth stoneware. It is here used upon grey stoneware, with raised dots in white, and colored with blue glaze. Incised decorations can also be executed upon earthenware in this way. White ware may be used, and the design drawn upon it in the “green” state. The piece may then be finished with colored glaze, which sinks into the depressions formed by the lines, and so gives them a darker color than the rest of the surface. Carved work can also be introduced with good effect as an accessory to incised work, and a few words as to this kind of decoration will now be in place.

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.