Profiles of the average aspect ratio in the disc midplane for runs with constant opacity after 400 orbits in Step B. The planet is kept fixed at 5.2 AU. The three different opacities that we use for later accretion rate measurements are used as running parameter. For κ = 0.01cm² g⁻¹ the gap becomes optically thin, and is then directly heated by the gap walls, which explains the higher gap temperature compared to κ = 0.1 cm² g⁻¹.