Double‐axis x‐ray spectrometer measurements at flat, low‐absorbing mosaic crystals produce broad and asymmetric Bragg‐reflection profiles. If the absorption coefficient changes during the sample preparation process, as in the case of graphite and graphite intercalation compounds, a determination of the instrumental profile is almost impossible. Using triple‐axis spectrometers, the Bragg‐reflection profiles are independent of the sample transparency, and peak profiles can be determined with high resolution and minor corrections.