See Supporting Figure for derivation of Equation . In ethanol, r increases more rapidly (in terms of percentage increase when compared to the same droplet in air) when increasing δ from 0 to 0.3 µm or equivalently F from 0 to 45 nN, with r num increasing from 0.15 to 1.65 µm and r exp increasing from 0.55 to 1.15 µm (an increase of between 2 and 10 times). We cannot resolve r exp < 0.5 µm because of the diffraction limit of the microscope. Therefore, we likely overestimate r exp values for small δ < 0.1 µm, which partly explains the discrepancy between r exp and r num .