Farblosglas

Farblosglas, or colorless glass, refers to glass that is visually transparent with little to no coloration. The term describes glasses that appear free of the greenish or brownish tint common in ordinary soda-lime glass, a result of very low iron oxide content and, in some cases, decolorizing additives during melting.

Most colorless glass is a form of soda-lime glass, though borosilicate and lead glass variants can be produced colorless as well. Achieving colorlessness requires careful control of raw materials and refining: using low-iron silica, decolorizers such as manganese dioxide or sulfur compounds, and removing gas inclusions during refining. In the float glass process, molten glass is cast on a tin bath to form flat, uniform sheets, while bottles and containers are formed by standard forming methods.

Optical properties include high transmittance in the visible spectrum and a neutral color balance, making Farblosglas suitable for applications where true color rendering is important. Its refractive index is close to 1.5, and its appearance is uniform across thickness, though deeper parts may appear slightly greener with higher iron content.

Applications include architectural glazing, display and storefront windows, automotive glazing, food and beverage packaging, light-guiding components, and laboratory or optical equipment where color neutrality is required. In marketing, “low-iron” or “extra-clear” are common commercial terms for the most colorless varieties.

Quality control relies on spectrophotometric color measurements and standard tests for clarity and surface quality. Farblosglas is valued for its neutral appearance, consistency, and compatibility with finishing and coating processes.