Systems and methods which utilize a plurality of reactive build compositions differing from one another in at least one material property and which may be applied, individually and/or in combination, layer upon layer to form solid three-dimensional objects having regions which vary in the at least one material property are provided. Further provided are systems and methods which utilize a plurality of reactive build compositions differing from one another in at least one material property and which may be applied, individually and/or in combination, layer upon layer to form a plurality of three-dimensional objects in a single solid freeform fabrication build, at least one object of the plurality of objects having a material property which differs from the same material property of at least one other object fabricated in the same build. Further provided are three-dimensional objects formed utilizing the disclosed systems and methods.