show flow maps in the y direction corresponding to w/x$_{c}$ = 8, w/x$_{c}$ = 11 and w/x$_{c}$ = 13 at the early growth stage. On the hydrophobic stripes, contact line growth is inhibited more effectively for narrow stripes, as can be seen from the intensity of the mass supplying regions depicted in the figure. For w/x$_{c}$ = 13, the effect is almost suppressed. The inflow to the hydrophobic stripe thus becomes almost equal to that of the homogeneous case. For much wider stripes, where the front is expected to break into several fingers, only those growing next to the hydrophilic stripes are expected to decrease their growth rate, while those located far from these boundaries should grow essentially as if they were in a homogeneous substrate. Anyhow, the film propagates faster on the hydrophilic stripes, so partial orientation of the film is achieved. Having characterized the dynamics on stripes of equal widths, it is straightforward to explore patterns where the stripes have disparate widths. In figures 8(a) and 8(b) we show the evolution of the contact line on a very thin hydrophilic (resp. hydrophobic) stripe that is placed next to a wide hydrophobic (resp. hydrophilic) stripe. In both cases, the wide stripe has a width equal to Λ$_{max}$, while the thin stripe is small enough to avoid the growth of the contact line. Figure 8(a) shows that, in contrast with the case of wide neighboring stripes, in this limit the substrate structure perturbs weakly the contact line growth, by increasing the velocity of the trailing edge because of the low resistance offered by the hydrophilic stripe. In contrast, figure 8(b) shows that the profile has almost converged to the sawtooth expected on a homogeneous hydrophilic substrate, but the trailing edge in the thin hydrophobic stripe decouples from the trailing edge of the sawtooth, and advances with a much smaller velocity. As a result, the film is oriented selectively on the hydrophilic channel, given that the width of the hydrophobic stripe remains much smaller than Λ$_{max}$. This limit is precisely the one reported experimentally by Kataoka and Troian [2], and by Kondic and Diez [19, 20] and Zhao and Marsall [3]. A particularly interesting feature of this regime is that one can regard the growth of the contact line as a fingering process, which emerges as a consequence of the longitudinal pattern, and not because of the linear instability of the contact line. As such, it is possible to control the width of the emerging fingers by tuning the width of the hydrophilic stripes. For large enough hydrophilic stripe widths, the contact line is expected to deform, giving rise to sawtooth structures. However, this is expected to modified the morphology of the front only, and not to alter the fingering imposed by the longitudinal pattern. 20