Congruent vaporization is a process that yields constant vapor species. Ti(2)O(3) was continuously electron-beam evaporated to produce titanium oxide thin films. Rutherford backscattering spectrometry was employed to study the evolution of the composition of these films. It seems that congruent vaporization can be established in a coating plant. TiO(2) films produced by conventional reactive deposition tend to contain mixtures of titanium oxides. Increasing the transmission of TiO(2) films becomes an issue of increasing the TiO(2) component in the films by adequate reactive evaporation.