Particle scale height evolution of runs SI30-4-2-d and SI30-4-4-d for about 300 orbits. Different particle sizes (marked with different colors) saturate to different scale heights, in such a way that H_p increases with decreasing Stokes number. Left panel: evolution of the run with the larger Stokes numbers (τ_s = 10⁻³−10⁰) in a 0.2 × 0.2 H_g simulation box. Right panel: convergence of the scale height for the larger species in a box that is twice the size of the original. The scale-height is relatively similar for the two box sizes, except for the two smallest particle size bins that exhibit an increased scale height when the box size is enlarged.