There are two length scales , wavelength and amplitude that characterize the observed morphologies. The wavelength of the instability was estimated from the fast Fourier Transform of the images, which were obtained using light microscopy. The data summarized in Figure show that the wavelength (𝜆) is rather independent of the salinity of the aqueous phase as well as the hydrophilic content of the H-PDMS, or if prepared either with polyacrylic acid or polyvinylalcohol as a sub-component. 𝜆 depends only on the thickness (h) of the coating, that too linearly, i.e. 𝜆 ≈ 2.6 ℎ. The prefactor (2.6) of the thickness is close to, but slightly lower than what was observed (3.8) previously with PDMS elastomeric films, when a rigid flat object adhering to those were removed by external forces. The exclusive dependence of the wavelength on the thickness, however, indicates that it results from the minimization of the elastic energy due to the longitudinal and the transverse shear deformations of the film as a periodic perturbation develops on its surface.