A method of additively manufacturing an object, the method comprising: selectively depositing build powder inside of a build contour of the object to form a build-powder section of a powder layer; selectively depositing support powder outside of the build contour to form a support-powder section of the powder layer; wherein: the build powder comprises a build-powder composition which is a mixture of a build-powder first constituent and a build-powder second constituent; the support powder comprises a support-powder composition; and the build-powder composition and the support-powder composition are different; and selectively controlling the build-powder composition of the build powder comprising selectively controlling a compositional ratio of the build-powder first constituent and the build-powder second constituent; wherein selectively controlling the build-powder composition of the build powder comprises selectively varying the build-powder composition of the build powder to achieve a powder gradient within the build-powder section of the powder layer; characterized by selectively controlling the build-powder composition and selectively depositing the build powder occur concurrently; and wherein selectively controlling the compositional ratio of the build-powder first constituent and the build-powder second constituent comprises: measuring a first mass of the build-powder first constituent; measuring a second mass of the build-powder second constituent; and measuring a mass of the build powder comprising the mixture of the build-powder first constituent and the build-powder second constituent. selectively depositing build powder inside of a build contour of the object to form a build-powder section of a powder layer; selectively depositing support powder outside of the build contour to form a support-powder section of the powder layer; wherein: the build powder comprises a build-powder composition which is a mixture of a build-powder first constituent and a build-powder second constituent; the support powder comprises a support-powder composition; and the build-powder composition and the support-powder composition are different; and selectively controlling the build-powder composition of the build powder comprising selectively controlling a compositional ratio of the build-powder first constituent and the build-powder second constituent; wherein selectively controlling the build-powder composition of the build powder comprises selectively varying the build-powder composition of the build powder to achieve a powder gradient within the build-powder section of the powder layer; characterized by selectively controlling the build-powder composition and selectively depositing the build powder occur concurrently; and wherein selectively controlling the compositional ratio of the build-powder first constituent and the build-powder second constituent comprises: measuring a first mass of the build-powder first constituent; measuring a second mass of the build-powder second constituent; and measuring a mass of the build powder comprising the mixture of the build-powder first constituent and the build-powder second constituent. the build powder comprises a build-powder composition which is a mixture of a build-powder first constituent and a build-powder second constituent; the support powder comprises a support-powder composition; and the build-powder composition and the support-powder composition are different; and selectively controlling the build-powder composition of the build powder comprising selectively controlling a compositional ratio of the build-powder first constituent and the build-powder second constituent; wherein selectively controlling the build-powder composition of the build powder comprises selectively varying the build-powder composition of the build powder to achieve a powder gradient within the build-powder section of the powder layer; characterized by selectively controlling the build-powder composition and selectively depositing the build powder occur concurrently; and wherein selectively controlling the compositional ratio of the build-powder first constituent and the build-powder second constituent comprises: measuring a first mass of the build-powder first constituent; measuring a second mass of the build-powder second constituent; and measuring a mass of the build powder comprising the mixture of the build-powder first constituent and the build-powder second constituent. measuring a first mass of the build-powder first constituent; measuring a second mass of the build-powder second constituent; and measuring a mass of the build powder comprising the mixture of the build-powder first constituent and the build-powder second constituent.