A curing system for printing of 3D objects having one or more sources of curing radiation moveably attached to and flanking at least one side of an extrusion head and extrusion nozzle wherein the extrusion head and extrusion nozzle and the at least one source of curing radiation act in unison as a single unit wherein curing of deposited curable material is applied concurrently with or immediately following deposition of the curable material.