Finally, 26 individual classes were obtained and the discriminating power of the spectroscopic analytical sequence was calculated to 0.98 (19 undifferentiated pairs for the 40 green spray paints).
In Figure 3 the complementarities between infrared and Raman techniques are illustrated, where each of the three methods used, i.e., infrared, Argon and Helium-Neon laser sources, supplies three different spectra for the group of non-differentiated paints 004,010,015,017,021 and 026.