Color composite (gri) VST image of the NGC 3640 group. The image size is ∼20 × 20 arcmin. North is up and east is to the left. The brightest group members are labelled in red on the image. The image is chosen as a target example for the VEGAS sample, given how clearly LSB features (μ_g > 29 mag arcsec⁻²) such as shells and tidal tails are evident in the outskirts of the central galaxy. Moreover, on the west side of NGC 3640, a LBS galaxy is also detected, with a very faint tail towards the BGG (Mirabile et al., in prep.). For this target, the fraction of IGL plus diffuse stellar envelope, estimated in Sect. 3 as ∼8%, comes mainly in the form of shells and tidal tails around the BGG.