Parametric cuts used for the selection of LSB candidates. The panels show g′−r′ colors (top panel), SBs (middle panel), and the concentration parameter, C (bottom panel of the galaxies), as a function of their r′-band apparent magnitude, m_r′. The selected galaxies (black symbols) and the galaxies rejected for being too red (red symbols), having too high of a SB (green symbols), and a too high C (blue symbols) are indicated with the different symbols. The black lines in the panels show the selection cuts (see the text and V18).