Use 1 part clay and 1 part stain for coating, and 50 or 60 parts clay and 1 part stain for staining through.
Fire blue paviors very hard.
Buff Terra-cotta Slip.—
| Buff fire clay | 16 parts |
| China clay | 6 parts |
| Yellow ocher | 3 parts |
| Ball clay | 10 parts |
| Flint | 4 parts |
Add water to the materials after mixing well, pass through the fine lawn, and dip the goods when soft in the liquid.
Transparent Glaze.—
| Ground flint glass | 4 parts |
| Ground white lead | 4 parts |
| Ground oxide of zinc | 1/4 part |
This glaze is suitable for bricks or tiles made of very good red clay, the natural color of the clay showing through the glaze. The goods must first be fired sufficiently hard to make them durable, afterwards glazed, and fired again. The glaze being comparatively soft will fuse at about half the heat required for the first burning. The glaze may be stained, if desired, with any of the colors given in glazed-brick recipes, in the following proportions: Stain, 1 part; glaze, 1 part.