Planck polarization angle maps for synchrotron emission, smoothed to 40′ FHWM (top) and thermal dust emission, smoothed to 10′ FWHM (bottom). Light blue and red colours indicate polarization angles aligned with meridians (ψ = 0deg) and parallels (ψ = 90deg), respectively, while yellow and purple indicate polarization angles rotated by −45 and + 45deg with respect to the local meridian in the HEALPix polarization angle convention. Colours are saturated at 10 μK_RJ.