Resulting radius distribution for all of our models for two different opacities after 3 Gyr evolution. The top row shows the resulting distribution after contraction with κ = 0.1κ_BL while the bottom row shows the resulting distribution with κ = 10κ_BL. Decreasing the opacity with a factor of 0.1 does not affect the final distribution significantly as contraction is already efficient in our nominal case. In contrast, increasing the opacity significantly slows down contraction such that a significant fraction of planets remain large at ~3–4 R_⊕.