Glaze — within the tiling context, refers to a glassy coating applied to the surface of a ceramic tile. It is a mixture of finely ground minerals and pigments that, when fired at high temperatures, fuses into a hard and vitreous layer. Glazes serve both decorative and functional purposes in tile manufacturing.

Decoratively, glazes add colour, texture, and visual appeal to the tile. They can range from glossy and transparent to matte and opaque, offering a wide variety of aesthetic options. Glazes can be formulated to replicate natural materials like stone or wood or to create vibrant and artistic designs.

Functionally, glazes provide a protective barrier for the tile surface. They make the tile impermeable to water, stains, and chemicals, increasing its durability and ease of maintenance. Glazes also contribute to the tile's resistance to scratching, abrasion, and fading, ensuring its longevity and performance.

The application of glaze is typically done by spraying, dipping, or brushing the liquid glaze onto the surface of the tile. After the glaze is applied, the tile is fired in a kiln at high temperatures, causing the glaze to melt and bond with the tile body. This firing process transforms the glaze into a durable and decorative coating.

Glaze formulation involves carefully selecting and combining various minerals, such as silica, feldspar, clay, and metal oxides, to achieve desired properties like colour, texture, and thermal expansion.