Lens modelling results of the two lenses: B1938+666 in the K′ Keck band (left) and J0946+1006 in the F814W band (right). For each lens, we present the result of the smooth model and the model that includes the NFW profile with free concentration. In each case, we show (i) the best-reconstructed model and critical lines, including both the light of the central galaxy and the main arc, (ii) the residuals between the data and the best model, calculated as (data-model) and (iii) the corresponding best-reconstructed source with the caustics. The posterior distributions for all models are shown in Fig. A.4 and A.5.