A method of manufacturing a wearable article may include providing a modular mold assembly that defines a mold cavity. The modular mold assembly may include a base and a first removable mold tool that interfits with the base. The base may have a mold surface partially defining the mold cavity and the first removable mold tool may have a mold surface disposed at and further defining the mold cavity of the modular mold assembly. A topography of the mold surface of the first removable mold tool may be nonuniform and different than a topography of the mold surface of the base. The method may include disposing polymeric material at the mold cavity, and then thermoforming a bladder in the mold cavity from the polymeric material. The bladder may have an outer surface with a nonuniform topography imparted by the topography of the mold surface of the first removable mold tool.