FIG. 9: Geometry of the asymmetric checkerboard pattern. The pattern is composed of alternated hydrophilic (grey) and hydrophobic (white) domains. In general, the width of the upper and lower domains is different, and the width of the lower domains is large enough to allow for the growth of unstable wavelengths that give rise to contact line growth on the hydrophobic domains and saturation to a sawtooth shape on the hydrophilic domains. The lengths of hydrophilic and hydrophobic domains, l$_{h}$ and l$_{φ}$ , can be chosen to fix a given fraction of hydrophilic covering. Wetting properties are fixed to θ$_{e}$ = 0 ◦ at the grey zones, while at the white zones θ$_{e}$ = 90 ◦ . FIG. 10: Contact line growth on asymmetric checkerboard patterns. Patterns are fixed by choosing l$_{h}$/x$_{c}$ = 1 . 3 and (a) f$_{CB}$ = 0 . 25, and (b) f$_{CB}$ = 0 . 62. The first plot corresponds to a transverse perturbation of the contact line at t/t$_{c}$ = 0. Subsequent plots are taken at time intervals of Δ t/t$_{c}$ = 67 . At the bottom of (a) and (b) we show the finger that grows in a homogeneous hydrophobic substrate for the same time as the last contact line snapshot of the checkerboard pattern. By comparing (a) and (b), it is observed that the length of the growing contact line, L , is smaller if the fraction of hydrophilic domains is small. 22 (a) (b)