Methods of forming a concave pattern, materials for forming a concave pattern and fabrication methods thereof, and products with a concave pattern

A method of forming a concave pattern is provided. The method includes providing a ceramic, tile or glass substrate and applying a ground glaze layer over a surface of the substrate. A material for forming a concave is applied over the surface of the substrate by a printing process. A firing process is performed to form a concave pattern in the ground glaze layer, wherein the concave pattern corresponds to an area of applying the material for forming a concave. Furthermore, materials for forming a concave and fabrication methods thereof and ceramics, tiles or glass products having a concave pattern are also provided.