Illustrations of the solar disc during the times of the observations for the Wallace flux atlas, observed by the Meudon spectroheliogram (Malherbe & Dalmasse 2019; Malherbe et al. 2023). The images shown are taken in the Ca II K line core, for the times when the atlas observations were taken for each wavelength band, which makes-up the complete Wallace flux atlas. The images contain observational artefacts seen as nearly vertical stripes, most likely caused by clouds.