The Ising rain stays mainly on the plane

We discuss a simple model describing coexistence of solid and vapour phases. The two phases are separated by an interface. We show that when the concentration of supersaturated vapour reaches the dew-point, the droplet of solid is created spontaneously on the interface, adding to it a monolayer of a visible size, while the vapour concentration drops down below the dew-point. Further increase of concentration results thus in the sequence of new monolayer creations. We discuss the resulting geometry. This is a joint work with Dima Ioffe.