Hardness-intensity diagram reporting the average intensity and hardness for each IXPE observation of Cyg X-1 performed. Hardness is defined as the ratio of photon counts in the 3.5–8 keV range to those in 2–3.5 keV. Circular, triangular, and square markers indicate observations in the soft, intermediate, and hard states, respectively. The color of each marker and the associated colorbar indicate the average IXPE hardness for each observation.