  The paper presents an analysis of the possible spectra manipulation and its
consequence for the specific application of XCT. The focus was on the
modification of the registered spectra dominantly by the sewing/stitching
method. A model spectrum was created to analyse the possible behaviour of the
spectral components when specifically arranged. The model and processing of
real experimental data revealed that careful spectral sewing can be a very
useful procedure and typically leads to improvement of the results obtained
with the XCT technique. The results recommended also cautiousness in the choice
of the applied modification and scale. In some cases gain or spectral
enhancement of a part of the spectrum can be considered also as a sort of
sewing, and improve the XCT results.
