Soap bubbles are by essence fragile and ephemeral. Depending on their composition and environment, bubble bursting can be triggered by gravity-induced drainage and/or the evaporation of the liquid and/or the presence of nuclei. In this paper, we design bubbles made of a composite liquid shell able to neutralize all these effects and keep their integrity in a standard atmosphere. This composite material is obtained in a simple way by replacing surfactants by partially-wetting microparticles and water by a water/glycerol mixture. A nonlinear model able to predict the evolution of these composite bubbles toward an equilibrium state is proposed and quantitatively compared to experimental data. This work unveils a composite liquid film with unique robustness, which can easily be manufactured to design complex objects.