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To mend a crack in clay that is only partially dry, put a little slip into the crack and then work in, with a modelling tool, clay of the consistency of the piece. If, after drying longer, the piece cracks again—a long, deep crack, that goes through to the inside—there is no way to mend it except by cutting the clay out on either side for quite a space beyond the crack, brushing both sides with slip, and filling in with clay as nearly as possible the consistency of the piece. This is pressed in in small bits, little by little, until the gap is filled. If it should crack again in small, short places, fill them with dry, powdered clay, pressed in and moulded with a steel tool.

In case of the piece cracking when it is bone dry—that is, after it has dried for several days and is pale-gray in colour—grind some pieces of baked clay to a fine powder, add enough water to make a soft, yellow paste, and fill the cracks with it.

The edge of the jar is cut as even as possible with a tool, and then made perfectly true by the following method: A little water is poured on a ground-glass slab, and the jar, held bottom up, is moved firmly but rapidly round and round on the wet surface, and then quickly taken up (by sliding it off at the edge of the slab) before it clings to the glass. The bottom must now be finished. The jar is first placed bottom up on a slab or table, then a circle is drawn with a pencil at about half an inch from the edge of the bottom. This is outlined with the pointed steel tool, and the bottom within the circle is evenly and carefully cut out with strokes of the oval, smooth-edged tool, so that the outside ring shall form a ridge not over one-sixteenth of an inch above the depressed interior of the circle. The potter now cuts his initial or mark, which is made in as simple lines as possible, into the bottom with firm, deep strokes. If the jar is not very dry, a wooden modelling tool may be used for this. Otherwise, the pointed steel tool is chosen. Care should be taken not to cut under the edge in making these incised lines. The edges should instead be bevelled, so that, when the glaze is put on, it will flow more freely over them.