Behavior of the total DR, dE(B − V)_max, with E(B − V) (top panel) and Galactic latitude (bottom panel). In each panel, orange symbols are the total DR computed within 80% of r_ℓ, red ones within r_h. The green line in the top panel is the 1:1 agreement, while the green dots in the bottom panel are the E(B − V) values of the sampled GCs. The gray-shaded areas cover the high-reddening sample (Sect. 4.2).