Comparison of RGS spectra of V3890 Sgr extracted during the dip (dark green shadings) and during time intervals excluding the dip and the initial rise (blue line). The top panel shows the full spectral range of interest, while the panels below zoom in to show more detail. The light grey shading is the Chandra LETGS spectrum of RS Oph taken on day 39.7 after outburst (Chandra ObsID 7296), scaled down by a factor of 5. See Sect. 3.2.3 for discussion. Labels with different colours for different ions are included at their rest wavelengths.