Minor-axis surface-brightness profiles versus the vertical distance z for two edge-on disc galaxies. a) and b) FGC 310, and c) and d) FGC 1285. Blue and purple lines in panels a) and c) show R-band profiles, and red lines i-band profiles. Model profiles are drawn with thick solid lines. Solid (dash-dotted) lines are profiles of convolved models using PSF_V,0m and PSF_i,0m (PSF_V,3m and PSF_i,3m), the purple line used PSF_K71. The black (grey) line shows the respective fitted combined thin-and-thick-disc model (single-disc model; of YD06). Crosses indicate R-band measurements that were extracted from Fig. 3 in DB00. The lower limiting radius r₁₁₀ – where the convolved models using PSF_V,0m, PSF_i,0m, and PSF_K71 lie ≥10 per cent above the input model – is marked with a coloured bullet that is surrounded by a black ring. b) Three colour profiles R − i are shown for: the model (thick solid line), the convolved model using PSF_V,0m and PSF_i,0m (solid line), and the convolved model using PSF_V,3m and PSF_i,3m (dash-dotted line).