He led the way to an ingenious machine which by means of compressed air was spraying a fine jet of color over the surface of a porcelain plate. In some places this color rippled away into a faint tint; in others it settled into an area of a deep rich tone. By the aid of stencils the effect produced was of an exquisitely shaded ware, and Theo watched the work with delight.
"I think this air-brush process is the most interesting one I have seen," the boy cried.
"It certainly is fascinating to watch, isn't it?" agreed Mr. Marwood. "I could stand here all day; but I fear we must go on, for we still have much to see. Let us go over to where those girls are gilding. Some of them are putting a fine gold line on the china, and others are doing elaborate designs in gold. The work of the next group is to gild the handles of cups and dishes."
They passed on and stood beside the workers.
"That does not look like gold!" exclaimed Theo, who viewed in astonishment the chocolate brown pigment that the girls were using.
Mr. Marwood laughed.
"All gold looks like that," he said, "before it is fired and burnished. In fact, all the mineral colors used to decorate glass, pottery, and porcelain look very different when they are put on from what they do after they have been subjected to the heat. That is the wonderful part of working in oxides and metallic colors. The beautiful hues we see on china or glass are the result of years of experiment. Never forget that. All china decorators have constantly to bear in mind the effect of a high temperature upon their colors. What would be attractive on the unfired clay might emerge from the kiln a very ugly product indeed. We must reckon on this fact."
Theo nodded.
"It must make the decoration of china a great problem," he said.
"It does. However, decorators have now learned pretty well what to expect. A certain carmine, for example, fires out violet. Many other shades fire lighter or darker than when applied, and allowance must be made for them. The girls who paint china become very skilful in estimating the changes in colors. These who are working beside us are doing the finest sort of porcelain decoration—faces, figures, and flowers. Those across the aisle are doing a vastly different type of work. They are putting coarse, sketchy flowers on the cheaper ware. Some of them, you will observe, are filling in designs that have either first been printed, or transferred by the decalcomania process, and must afterward be finished by hand. The girls supply the dabs of color that are needed to complete the pattern."