Log–log scatter plot of the intensity excess and B_los at a) the continuum and b) the core of the Fe I 6173 Å line, and c) 1700 Å. The intensity excess is given in units of ppm of the disc-integrated quiet-Sun intensity. The plot points, colour-coded by μ, denote the result of grouping the network and facular image pixels with similar B_los and μ together, and taking the average intensity excess. See Sect. 4.6.