Histogram of the relative orientations (HRO) between the iso-N_H contours and the magnetic field orientation inferred from the BLASTPol observations at 250 μm obtained with the three diffuse emission subtraction (DES) methods, namely aggressive, intermediate, and conservative, defined in Sect. 3.1. The figures present the HROs for the lowest bin, an intermediate bin, and the highest N_H bin (blue, orange, and dark red, respectively). The bins have equal numbers of selected pixels within the N_H ranges labelled. The horizontal dashed line corresponds to the average. The widths of the shaded areas for each histogram correspond to the 1σ uncertainties related to the histogram binning operation. Histograms peaking at 0deg would correspond to being predominantly aligned with iso-N_H contours, while histograms peaking at 90deg would correspond to predominantly perpendicular to iso-N_H contours.