Example of the background subtraction process applied to the calibrated slope image cutouts between Stage 2 and Stage 3 of the JWST Science Calibration Pipeline. Top panel: cutout for one source showing the dispersion of the spectrum (central rows). Rows above and below the spectral trail have a purple hue indicative of the background, which increases in strength toward longer wavelengths. Bottom panel: following background subtraction, the cutout now only shows significant flux from the source. The color scale is the same for both panels. Data inside the shaded regions are ignored when analyzing the 1D spectrum in the following analysis. White pixels are “NaN” values that do not affect the spectral extraction.