We study metastable PolyDimethylSiloxane (PDMS) films deposited on a s
ubstrate of fluorinated PDMS: after nucleation, a hole grows at consta
nt velocity V. V is inversely proportional to the substrate viscosity
and is proportional to -S, where S(< 0) is the spreading parameter. Th
e velocity is a decreasing function of the film thickness e; the detai
led V(e) law can be interpreted by a balance between capillary forces
and viscous forces acting on an almost flat rim.