Lensing stacking on CIB peaks. This figure first appeared as Fig. 4 of Planck Collaboration XVIII (2014), a paper devoted to studying the gravitational lensing-infrared background correlation. It shows temperature maps of size 1 deg² at 545 GHz stacked on the 20 000 brightest peaks (left column), troughs (centre column), and random map locations (right column). The stacked (averaged) temperature maps are in K. The arrows indicate the lensing deflection angle deduced from the gradient of the band-pass filtered lensing potential map stacked on the same peaks. The longest arrow corresponds to a deflection of 63, which is only a fraction of the total deflection angle because of our filtering. This stacking allows us to visualize in real space the lensing of the CMB by the potential wells traced by galaxies that generate the CIB. This vividly demonstrates that our lensing map, albeit noisy, is well correlated with a high-z tracer; it also warrants using the CIB as a lensing potential tracer at smaller scales (and in other experiments).