Cut through rectified echelle order five of GD71 (VIS), which is intersected by two adjacent bad columns on the raw frame. The top panel shows the uncorrected PSF (black curve), the weighted spline fit (blue curve) and the weighted linear combination of both (red curve). The solid circles show the grid locations that are used as break points for the spline fit. The weighting factors are based on the pixel badness as depicted in the bottom panel. The thresholds for the spline break points (blue dashed line) and the weighted linear combination (red dash-dotted line) are overplotted.