Mass-radius relation with selected WDs highlighted from 50 kK downward (left panel), and hydrogen mass vs. effective temperature (right panel). The dots correspond to their values at 10, 20, 30, 40, and 50 kK, and each color corresponds to a different WD. The two figures use the same color code. Labels correspond to the notation of Table 1. The hydrogen depletion is due to residual nuclear burning along the final cooling track.