next hydrophobic domain. At a given time, comparing the contact line for both l$_{φ}$ values shows that the leading edge is located at a slightly more advanced position for the smaller l$_{φ}$ , whereas the trailing edge is located at a slightly less advanced position. This means that the leading edge advances faster for small l$_{φ}$ . This occurs because the resistance to contact line motion is smaller in this case, given that f$_{CB}$ is large. Conversely, at small l$_{φ}$ , the trailing edge has to sweep increasingly long hydrophobic domains, thus decreasing its velocity. Still, whatever the value of l$_{φ}$ , the comparison to the homogeneous substrate shown in figure 10 clearly shows that the contact line grows to smaller lengths as a consequence of the checkerboard pattern. In figure 12 we plot the growth rate of the contact line as a function of the length of the hydrophobic domains. The limiting cases ˙ L ( l$_{φ}$ = 0) and ˙ L ( l$_{φ}$ → ∞ ) correspond to the growth rates of the contact line in the adjacent stripe patterns of figures 8(b) and 8(a), given that w$_{h}$ and w$_{φ}$ are chosen to be equal to the stripe widths of those patterns. For intermediate l$_{φ}$ , we observe a monotonous decrease from one value to the other. 

Increasing the width of the thin domains, w$_{h}$ , does not modify the dynamics of the film qualitatively, as long as this width is much smaller than Λ$_{max}$. This changes as w$_{h}$ becomes comparable to Λ$_{max}$; in this case the contact line destabilizes in both domains, giving rise to the growth of a different structure. Figure 11 shows the contact line growth on equally wide domains, of width equal to Λ$_{max}$. In this case, there are two fronts that grow with the same velocity. Each front grows as a finger when in contact with a hydrophobic domain, and spreads on the following hydrophilic domain periodically. At long times, the net growth rate of the contact line achieves a constant value. 

Thus, for both symmetric and asymmetric configurations, the checkerboard pattern in- troduces the effect of spreading on hydrophilic domains, relaxing the growth of a finger momentarily. For asymmetric patterns, this provides a way to tune the growth rate of the contact line. In the following section we will propose a kinematical model to account for the growth of the contact line in terms of the geometrical parameters of the checkerboard pattern. 

