Interior wall tiles are a type of ceramic tiles, primarily used for indoor wall decoration. They consist of three parts: the body, the base glaze layer, and the surface glaze layer. The water absorption rate of the body is usually around 10-18%. The weight of the base glaze applied is 40-60 grams, while the surface glaze is 90-160 grams. Generally, the higher the firing temperature, the greater the surface glaze weight, resulting in better brightness and a smoother glaze surface. Of course, the quality of the glaze material also has a significant impact.

Inspection Standards: 1. For wall tiles, there should be no hollow spots on the surfaces. Hollow spots are permissible at the edges of tiles, but no more than three such spots are allowed in a single room. You can use this standard to inspect the wall tiles in our indoor kitchen and bathroom.

2. The standard for verticality is that the verticality of the tile's facade must be controlled within 3mm. Otherwise, it is not qualified.

3. The standard requirement for flatness is that the tiles must not have a flatness error exceeding 2mm, and the height difference between adjacent tiles should not exceed 0.5mm. Tiles exceeding the error are considered不合格, and we can request them to be removed and re-laid.

4. Tiling joint levelness, whether horizontal or vertical, must not exceed 0.5mm. In fact, it's visible to the naked eye if it does. Additionally, measure the tiling joint's vertical and horizontal levelness before applying the grout, as the grout can cover up imperfections, making it difficult for us to measure later.