The craft of ceramic tile manufacturing is extremely old. The Egyptians were using Nile mud to make tiles over 6000 years ago and were applying glaze finishes several thousand years before the Romans laid tile floors in Great Britain. Many of the floors are in perfect condition even today giving evidence of their outstanding durability.
Tiles may be compounded clay bodies consisting of clay, 30 to 35%, which is the plastic; flint, 10 to 15%, which is the filler; and feldspar, 45 to 50%, which is the fluxing agent that fuses the ingredients into a solid mass. Tiles are also made from one or more naturally occurring clays. They are either glazed, having a glassy surface fused upon their face, or unglazed, being composed of the same ingredients throughout. They may be classified as non-vitreous, semi-vitreous, vitreous or impervious, which indicates the degree of fusion. In the dust-pressed process, steel dies apply heavy pressure to a damp ceramic mix. In the plastic process, considerable more water is used and the clay is then shaped.
When tile bodies composed of various silicates are subjected to high temperatures, new complex silicates are formed. The result is a strong, hard product with non-fading colors. A prominent floor tile is the ceramic mosaic tile. This is the familiar small tile, an inch or two on the side, fully vitrified and usually unglazed. Pavers are unglazed tiles resembling ceramic mosaic but larger in size, usually three by three to six by six inches. Quarry tiles are unglazed, made from one by one to twelve by twelve inches. The word quarry comes from the French word, “carreau”, meaning a square or paving tile. Faience tiles have highly colored glazes, a rugged artistic appearance and come in a large variety of sizes.
