DIB to extinction ratio EW/A_v as a functionof τ₃₅₃ for all APOGEE sightlines with EW ≥ 0.03 Å and A_v ≥ 0.2 mag. These limitations ensure a reliable determination of the EW/A_v ratio. Orion, Taurus, and Cepheus targets are marked by black signs, while all other targets are color-coded according to the Galactic latitude. Here, one can distinguish three different regimes: high-latitude, low dust sightlines that correspond to nearby diffuse clouds, and a high EW/A_v of ≃ 0.23 Å mag⁻¹; partially mixed phases in nearby off-plane cloud complexes following the Taurus-Orion-Cepheus trend (red curve); and distant, high-dust-optical-depth sightlines within the midplane for which the EW/A_v ratio reachesa constant value of ≃ 0.056 Å mag⁻¹ (blue dashed curve).