Relative differences of the cooling times as a function of the surface luminosity, among different evolutionary models of a 1.0 M_⊙ DA WD. The dotted line displays the difference between calculations with C07 and B20 opacities (B20 cooling times minus C07 values at the same luminosity), the dot-dashed line the difference between B20sd and C07 calculations, and the solid line the difference between B20wd and C07 models.