Production of coloured soda-lime-silica glasses either as tableware and containers or as flat glass, exhibits many similarities. In addition to colour generation, basic glass composition and glass redox state are two aspects that should be considered in the production of all coloured soda-lime-silica glasses. Basic glass composition directly affects the glass crystallisation temperature, an important physical property of coloured glasses that are less transparent to infrared radiation, and density, a property that should be followed if the colourant amount in the glass composition is high. Glass redox state is another important parameter since, in addition to its impact on colour, it is highly effective on the fining action of sulphur compounds, the major refining agent of most soda-lime-silica glasses.
