Logarithm of the outer mass fraction from the boundary where the magnetic field is expected to be trapped, i.e., the MB, in terms of WD mass. We plot the theoretical predictions for CO WDs from Miller Bertolami (2016) and Dominguez et al. (1999), and the Full-Network Repository of Updated Isotopic Tables & Yields (FRUITY) database (Cristallo et al. 2015), and those for oxygen-neon (ONe) WDs from Siess (2010) and Limongi et al. (2024). These models consider different metallicities spreading around the solar value. A cubic polynomial fit to the data with M_WD > 0.575 M_⊙ is shown with a solid black line. A deviation of ±0.30 from the cubic fit is shown using dotted black lines, which comprises all models considered in this work.