Do soft solids have strain-dependent surface tension?

Xu et al. observed (Nat. Commun. 2017) that the opening angle below a wetting ridge increased with the far-field stretch of the substrate. Using a Neumann triangle, this was interpreted to correspond to an increase in the surface tension with strain. Masurel et al. (Phys. Rev. Let. 2019) argued that the coupling between nonlinear bulk elasticity and the geometric singularity at the tip of the wetting ridge suffice to explain the experiments of Xu et al, without invoking the Shuttleworth effect. Here, we describe new experiments investigating possible strain-dependence of the surface tension of a soft solid, in the absence of potentially confounding geometric singularities.