A method for making an article having a cavity extending inwardly from an outside surface, the method comprising the steps of: a) three-dimensional binder jet printing a three-dimensional binder jet article from a build material, wherein the three-dimensional binder jet article is a three-dimensional binder jet version of the article; b) three-dimensional binder jet printing from the build material a three-dimensional binder jet object which is adapted to be contactingly insertable into the cavity of the three-dimensional binder jet article, contactingly insertable meaning that at least a portion of the three-dimensional binder jet object can be inserted into the cavity of the three-dimensional binder jet article in such a way that at least opposing portions of an outer surface of the three-dimensional binder jet object contact at least opposing portions of a surface of the cavity in a manner which provides structural support for higher of contacted walls of the three-dimensional binder jet article cavity from warpage during heat treatment; c) coating with an interface material or applying a material to at least one of at least a portion of the surface of the cavity and at least a portion of the surface of the three-dimensional binder jet object to prevent the three-dimensional binder jet object from becoming bonded to the three-dimensional binder jet article during step (e) hereof; d) contactingly inserting the three-dimensional binder jet object into the three-dimensional binder jet article cavity; e) heat treating the three-dimensional binder jet article and three-dimensional binder jet object to transform the three-dimensional binder jet article and the three-dimensional binder jet object into, respectively, the article and a heat treated three-dimensional binder jet object; and f) removing the heat treated three-dimensional binder jet object from the article. a) three-dimensional binder jet printing a three-dimensional binder jet article from a build material, wherein the three-dimensional binder jet article is a three-dimensional binder jet version of the article; b) three-dimensional binder jet printing from the build material a three-dimensional binder jet object which is adapted to be contactingly insertable into the cavity of the three-dimensional binder jet article, contactingly insertable meaning that at least a portion of the three-dimensional binder jet object can be inserted into the cavity of the three-dimensional binder jet article in such a way that at least opposing portions of an outer surface of the three-dimensional binder jet object contact at least opposing portions of a surface of the cavity in a manner which provides structural support for higher of contacted walls of the three-dimensional binder jet article cavity from warpage during heat treatment; c) coating with an interface material or applying a material to at least one of at least a portion of the surface of the cavity and at least a portion of the surface of the three-dimensional binder jet object to prevent the three-dimensional binder jet object from becoming bonded to the three-dimensional binder jet article during step (e) hereof; d) contactingly inserting the three-dimensional binder jet object into the three-dimensional binder jet article cavity; e) heat treating the three-dimensional binder jet article and three-dimensional binder jet object to transform the three-dimensional binder jet article and the three-dimensional binder jet object into, respectively, the article and a heat treated three-dimensional binder jet object; and f) removing the heat treated three-dimensional binder jet object from the article.