Movie S2.

Inteferograms from single bubble experiments in Group I and IV base oil, and a silicone oil mixture (0.5% 2cSt in 50 cSt) showing the observed spontaneous dimpling. The more foaming multicomponent Group I base oil shows spontaneous dimpling (open experiment) while the less foaming homogeneous Group IV base oil does not. Open experiments with the silicone oil mixture shows spontaneous dimpling, while when evaporation is suppressed, spontaneous dimpling is suppressed as well - consequently reducing the bubble stability against coalescence.