ACID CLEANER — water-soluble substance with an acid pH used to clean tile and mosaic surfaces after installation. Acid cleaners are corrosive and should be used with adequate precautions. The surfaces must be rinsed with clean water after use.
Acroterion — A terracotta ornament at the top or side angle of a roof pediment, common in Greek, Etruscan and Roman architecture.
ACRYLIC (ADDITIVE) — A liquid additive that increases the strength and flexibility of adhesive and grout.
ACRYLIC PAINT — Water-based paint made of pigment suspended in acrylic polymer emulsion and plasticizers, silicone oils, defoamers, stabilizers, or metal soaps. It can be used to add colour to grout and to paint exposed wooden surfaces on a mosaic base, such as the edges of panels and legs of chairs.
ADHESIVE — Generic term for a wide range of substances used to bond tile, tesserae or mosaics to a temporary and / or permanent backing.
Adobe — A sun-dried brick made from mud and straw.
Alkaline glaze — A relatively low-fired glaze with a high concentration of alkali elements, such as wood or plant ash, in its composition.
ANDAMENTO — Within the mosaic context, andamento means the movement or flow of tesserae. Andamento directs the eye and must be in harmony and agreement with the subject to be interpreted and the available space.
Antefix — A terracotta ornament concealing the ends of roof tiles common in Greek, Etruscan and Roman architecture.
Architectural ceramics — Generic term for all kinds of moulded architectural ceramic ornament, whether glazed or unglazed.
Arista — Spanish for 'ridge'. The design is formed by ridges on the tile. Coloured glazes are then put into each space and are kept apart by the ridges.
Art tile — The term used in the second half of the 19th century for tiles showing the influence of the design movements of the day, and often having a special aesthetic quality.
AXES — Horizontal or vertical lines that are drawn at specific places and used as a reference to lay tiles on walls and floors.
Azulejos — Spanish and Portuguese word for 'tiles'.
