ORFET is a transparent, greenish-blue, almost odourless, glass-glass staining fluid, based on complex, acidic fluoride compounds, which react on the surface to create an acquired, white layer that, when washed off, shows the changed appearance of a transparent semi-gloss. It is always used as it is, either for use in a bath or for spraying or screen printing. Depending on the time of exposure, the glass objects take on a satin to white appearance which differs from sandblasting mainly in the difficulty of staining from the environment and the presence of matt opacity and in hidden places.