Continuum of GX 3+1. HEG (light blue) and MEG (dark blue) data from seven datasets were used to fit the continuum. We stacked and binned the observations for display purpose only. The average fit of the seven data sets is shown with a red solid line. The model consists of a black body (in black) and a power law (green) with a photoelectric absorption component with N_H ≃ 1.9 × 10²² cm⁻². In the bottom panel we show the relative residuals defined as (observed-model)/error. The residual around 8 Å is due to the uncertainty on calibration for the aluminium K-edge.