Droplets on lubricated surfaces: The slow dynamics of skirt formation

A key question in the interaction of droplets with lubricated and liquid-infused surfaces is what determines apparent contact angle droplets. Previous work has determined this using measured values geometry `skirt' -- meniscus-like deformation that forms around base deposited droplet. Here, we consider theoretically equilibrium a droplet on smooth, impermeable lubricant-coated surface, argue small effect gravity within skirt size substrate are important for determining final equilibrium. However, also show evolution towards ultimate extremely slow (on order days typical experimental parameter values). We therefore suggest previous experiments smooth may have observed only slowly-evolving transients, rather than `true' equilibria, potentially explaining why wide range sizes been reported.