Rosseland, Planck, and stellar mean opacities (from left to right) as a function of temperature for grains of sizes 0.1, 1, 10, 100 μm, 1 mm, and 1 cm. They are independent of the gas density because they are dominated by the dust component. These values were calculated using RADMC-3D for a mixture of 50% silicates, 50% ice, and disc dust-to-gas ratio of 1%. The gray vertical line shows the location of the water iceline transition (170 K ± 10 K), causing a transition in opacity due to the evaporation/condensation of dust grains.