JWST/MIRI F1130W observations towards three M-type supergiants in Westerlund 1. These are W26, W2O, and W237 from top to bottom and in order of decreasing declination. The colour bar units are MJy ster⁻¹. In each case the central white pixels are saturated. The stars denote the positions of the three target supergiants. The colour scale is the same as the synthetic observations in Fig. 7.