Described are the principles of calculation, the methodology and the results of laboratory tests of grazing incidence mirrors used in solar X-ray telescopes installed in rockets "Vertikal 8" (1979), "Vertikal 9" (1981) and "Vertikal 11" (1983) launched as part of the
Intercosmos programme. The X-ray grazing incidence mirrors were developed in the Astronomical Institute of the Czechoslovak Academy of Sciences using galvanoplastic replica technology and tested in the Lebedev Institute of Physics of the USSR Academy of Sciences according to a chart design with one of the investigated mirrors acting as a collimator. The advantages and drawbacks
of this test method of X-ray mirrors are analysed.