Small part of a single bias and scattered-light subtracted flatfield frame normalized by the trace profile. The pink dashed line indicates the estimated trace center. As expected, there is no structure in vertical direction. The only visible effect is increased noise towards the upper and lower edge of the trace. The vertical striping represents the individual pixel sensitivities but is mostly related to bad pixels. The striping, i.e., variations in dispersion direction, is of no concern since it will be removed by the de-blazing and flux calibration procedures.