SDSS-DR17 three-colour images of three selected SIT triplets as an example of systems with interacting galaxies (image scale 0.215″ pixel⁻¹), and one selected triplet as an example of a relaxed galaxy triplet (image scale 1.067″ pixel⁻¹). Upper left panel: SIT 133 (TCE triplet). Upper right panel: SIT 263 (TCE triplet). Lower left panel: SIT 45 (TL triplet). Lower right panel: SIT 190 (TE triplet), a relaxed isolated triplet with Q_trip = −2.72 and H₀t_c = 0.16. Since the scale is larger to cover the full triplet, a line has been added for an easier identification of the B and C galaxies and to avoid confusion with background and foreground galaxies.