Porcelain & Ceramic Tile Glossary

Ceramic: A fired clay material. Click here to learn more about the development of ceramic on our blog.

Double-fired or Bicottura tiles: Double-fired or Bicottura tiles are glazed ceramic tiles produced by a procedure that breaks the firing process in two phases. An initial firing of the shaped raw materials produces a hard tile body or bisque and then a re-firing of the bisque takes place once the glaze or decoration has been applied. Usually, there are two glazes on the tile, first a non-transparent glaze on the body, then a transparent glaze on the surface. Double-fired tiles have sophisticated finishes with deeper shine and sharper colors.

Dust-pressed tiles: Dust pressed tiles are formed by the dust pressed method in which the finely grinded clay and raw materials are shaped in molds at high pressure before firing. Dry-pressed tiles are consistent with regard to their overall dimension. This method is also efficient and cost effective.

Extruded tile: Extruded tiles are formed by a process in which the wet clay or plastic raw material is forced through a mold and then cut into shape before firing. These tiles are less dimensionally consistent than pressed tiles. Extruded tiles include rustic styles such as terra cotta and clinker. These tiles are often used outside or where a rustic effect is wanted.

Single extruded tiles are produced in a long slab, which is then cut to shape while double-extruded tiles, also known as split tiles, are produced in a column that must be split before tiles are cut.

Finish: This is the textural or visual characteristic of a tile surface. For glazed tile this may be bright or high gloss, satin or matte. Also, for both glazed and unglazed tiles, the finish can be flashed, textured, polished, raised, embossed, dimpled, etched, scored, ribbed etc.

Glaze: When tiles are decorated with natural and artificial colors through a second firing process.

Grout: Filling powder form in premixed colors used to fill the joints between tiles.

Impervious stoneware tile: Dust-pressed ceramic tiles with water absorption levels less than 0.5% are known as impervious stoneware tiles. They also have high mechanical and chemical characteristics. Also known as Fully Vitrified Stoneware or Porcelain Stoneware, these tiles are often recommended for exterior installations.

ISO: ISO is the abbreviation of International Standards Organization, a worldwide network of the national standards institutes of 157 countries. It has also drafted international standards (ISO/TC 189 “Ceramic Tiles”) for ceramic tiles. ISO Standards are used by tile manufacturers worldwide.

Mosaic tile: Small tiles connected in a pattern using a mesh backing that can either be used as an accent or as a full wall or floor.

Non-rectified, or standard, tiles: These are produced so that there are slight variations in tile size.

Pattern: A design engraved in outline on the surface of the tile, or carved in relief pressed into the tile.

PEI classes or ratings: Porcelain Enamel Institute rating scale which represents the amount of foot traffic that a tile can handle.

Porcelain: a specific type of ceramic that has unique features such as a high density and durability.

Rectified tile: Goes through a manufacturing process to assure each tile is exactly the same size and shape, and therefore it is possible to lay them cleanly and carefully with very little grout.

Saltillo tile: A porous tile in a range  of tones of red which, while beautiful, should not be used in rooms that have a lot of water splashing, like the bathroom or kitchen.

Single-fired/Monocottura tiles: Monocottura is an Italian word meaning “single-fired”. In this method, individual tiles are shaped, glazed and fired in one step, at the same time. These tiles are also known as Monocottura tiles. They may be glazed or unglazed. Single-fired tiles are much stronger, with better glaze adhesion.

Thin-set: An adhesive mortar made of cement, fine sand and a water retaining agent, used to attach tiles to the underflooring.