Ultrathin plate-like colloidal particles are effective candidates for Pickering stabilization of water-in-water emulsions, a stabilization that is complicated by the thickness and ultralow tension of the water–water interface. Plate-like particles have the advantage of blocking much of the interface while simultaneously having a low mass. Additionally, the amount of blocked interface is practically independent of the equilibrium contact angle θ at which the water–water interface contacts the nanoplates. As a result, the adsorption of nanoplates is stronger than for spheres with the same maximal cross section, except if θ = 90°.