When taken out of the first oven the ware is termed "biscuit." It is now ready for glazing. Of course, in such ware as jasper or unglazed stoneware, basalt, and similar kinds, the "biscuit" state is the final one, the object being completed.
=The Dipping-house.=--In the illustration (p. 57) it will be seen that the ware in its "biscuit" state is dipped in liquid glaze in a very deft manner, after which it proceeds to the "glost" oven to harden this glaze on its surface.
It is here that great care has to be exercised in keeping the pieces from coming in contact with each other; spurs and tripods are placed between each piece to obviate this. The "saggers" in which this newly-glazed ware is placed are dusted with material infusible at the lower heat to prevent the pieces adhering to these "saggers." In fact, as is readily seen, a fine specimen may be easily ruined at any stage.
In undecorated ware, as in the cream-ware examples illustrated (p. 225), this ends the process, and they are complete. But in ware that is to be decorated _over_ the glaze there is yet another stage before they are finished.
It will be observed that we are alluding to _over-glaze_ decoration. But ware may be painted before being glazed,--that is _under-glaze_. In order, however, not to confuse the beginner at the outset, this has been described in a later chapter (p. 326).
=The Enamel Kiln.=--After the decorations have been painted upon the glazed ware it has to be fired in the enamel kiln. A far lower heat than that of the "glost" oven is required; the flames do not pass inside the kiln, as in an oven, but are led in flues all round the kiln. We give an illustration (p. 61) of this for firing colours or gold _over_ the glaze. As will be seen, the pieces are carefully protected from contact with each other, and at this last stage it is quite possible to undo all the patient labour previously employed and irretrievably ruin a piece.
In this hasty outline of the various processes of the potter much has been omitted; but, in the main, these illustrations should serve to kindle a more intelligent interest, even among collectors, in the earthenware and china which has passed through so many critical periods in its life-history.