Glossary

Shade variation is the term used when the surface of a tile is intentionally not uniform in colour and tone. These variations in colour within the same tile collection are used to reproduce textures that evoke natural materials such as stone or marble. In the case of a wood effect, shade variation can provide a distressed, time-worn appearance.

The size refers both to the shape of the tile, which may be square, rectangular, hexagonal or irregular, and the dimensions of the sides, on which basis tiles are classified as small, medium and large size. In general, tiles over 120 cm are defined as large size tiles or ceramic slabs. When choosing the most suitable size, consideration must be given to the type of location, the size of the interior, whether or not there is natural light, its intended use and the desired style.

Normally, when tiles are over 120 cm in size they are defined as ceramic slabs. Apart from their size and appearance, the installation method is also different from that used for smaller tiles. The installation of slabs requires special care, with the use of specific equipment, the right adhesive and the correct adhesive application procedure. Porcelain stoneware slabs are particularly attractive and are being more and more widely used in architectural and interior design projects and in locations where continuity between the floor and wall covering or between different rooms is required.

There are different degrees of slip resistance and different methods for measuring it. The most widely used method is a German test, which awards an R value. The lowest value is R9 and the highest is R13. A higher anti-slip resistance coefficient is obtained during production by adding abrasive particles to the surface glaze, or by the creation of relief textures or ribbing.

In physics, friction is defined as a force opposing the movement of an object in relation to its contact surface. If the object is not moving in relation to the surface, friction is static; if the object is moving in relation to the surface, friction is dynamic. In ceramics, and for floor tiles in particular, the friction coefficient is used as a parameter for assessing tiles’ anti-slip capabilities.

Static friction coefficients are classified as follows:
≤ 0.50: Dangerously slippery
0.50 – 0-60: Satisfactory grip
≥ 0.60: Anti-slip

Dynamic friction coefficients are mainly tested using the Italian BCRA standard and the American standard, although the new EN 16165 standard APPENDIX B is considered the most widely used standard in Europe. Its classification is as follows:
R9: Normal grip – from 3° to 10°
R10: Medium grip – from 10° to 19°
R11: High grip – from 19° to 27°
R12: Strong grip – from 27° to 35°
R13: Very strong grip – gradient over 35°

Stoneware objects (pottery to contain food or water) dating from about eighteen thousand years ago have been found in the Middle East. Today, the main objects industrially produced in stoneware are floor and wall tiles. Porcelain stoneware, a particularly compact ceramic material, is widely used in contexts of all kinds, due to its countless mechanical, functional and aesthetic qualities: very low water absorption; resistance to abrasion; resistance to foot traffic, wear and time; resistance to chemical and weather; compactness, versatility and very high aesthetic impact.

Tiles’ surface finish is produced by a variety of different processes depending on the appearance required.
The natural finish, for example, is the most widely used and the most versatile.
The shine finish, on the other hand, is produced by honing the ceramic surface to create a luxurious “mirror” effect. It is often used on ceramic slabs for a particularly glossy, glassy surface, and to increase their impression of depth.