Stacked spectra at different distances along the sightlines of the Perseus, Taurus, Orion A, and Orion B molecular clouds. The top panels correspond to Fig. 8, with shaded regions indicating distinct distance intervals. For Perseus, four intervals are defined: before the first intensity jump, between the first and second jumps, during the second jump, and beyond the second jump. For Taurus, the intervals are divided into four distance ranges: before the jump, during the jump, after the jump within 100 pc, and beyond up to 600 pc. For Orion A and Orion B, the distances are grouped into three intervals: before the jump, during the jump, and after the jump. The bottom panels show the stacked spectra of DIB λ6614 for each distance interval across the four molecular clouds, with error bars indicating the uncertainties in flux measurements. Each stacked spectrum displays a Gaussian fit to the DIB feature, with the EW₆₆₁₄ and σ₆₆₁₄ annotated. The color shading in the top panels corresponds to the colors of the stacked spectra in the bottom panels.