Sodium silicate, also known as soda glass, is an inorganic substance with the chemical formula Na₂SiO₃. Its aqueous solution is called water glass, and it comes in colorless, greenish, or brown solids or viscous liquids. It is widely used in foundry, papermaking, sand casting, pattern making, paper tube and box bonding, construction, carbon black, subway construction, gold and silver foil lamination, ceramics, alkali for silica sol, and other applications. It can also be customized into various liquid sodium silicate products according to customer requirements.