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What is borax used for in glassmaking and pottery glazes?

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A labeled diagram of the periodic table entry for boron shows its atomic number 5, symbol B, electron configuration, atomic weight range, and classification as a solid, weakly acidic, other nonmetal with a rhombohedral crystal structure at room temperature. — boron Properties of boron.

Borax, or sodium tetraborate decahydrate, serves as a vital component in the production of glass and pottery glazes within the ceramics industry.12

In these applications, borax acts as a flux, a substance that promotes fusion by lowering the melting temperature of the materials being processed. By reducing the viscosity of the molten mixture, it helps ensure a smoother, more uniform finish in both glass manufacturing and the creation of decorative or protective ceramic glazes.12