3.6 μm radial surface brightness profiles normalized with the exponential disc surface brightness (μ_exp), and disc scalelengths (h_r), of the two dimensional decomposition values from Spitzer Survey of Stellar Structure in Galaxies Pipeline 4 (S⁴G P4, Salo et al. 2015). A single exponential disc would appear as horizontal line in this plot (grey lines). In the left panel we show a random sample of 18 low mass galaxies, which are not part of this study but fulfil the inclination criteria of the sample selection (b/a> 0.5). In the right panel we show random sample of 18 high mass galaxies with Type I, II, and III disc profiles, which are part of this study. In the high mass galaxies we show the location of the Type II or III break by a short vertical line segment. All the profiles have been cut by the μ = 25.5 mag arcsec^-2 radius of the 3.6 μm data.