Absorption minimum velocity measurements for a selection of spectral lines in iPTF13bvn (squares) and PTF12os (circles). The velocity of He i λ5876 is shown in red, He i λ6678 in cyan, and He i λ7065 in pink. The Fe ii λ5169 absorption minimum velocities are shown in gray. We also indicate the estimated H α (blue) and H β (teal) velocities for both PTF12os and iPTF13bvn. The dashed lines show the photospheric velocity evolution of our best-fitting hydrodynamical models for SN 2011dh (gray), PTF12os (blue), and iPTF13bvn (red).