A method of manufacturing an object. A thermoplastic matrix material is melted to transform it into liquid matrix material. The liquid matrix material is fed into a chamber via one or more matrix inlets. A fiber is also fed into the chamber via a fiber inlet. The fiber in the chamber is contacted by the liquid matrix material. A coated fiber is extruded from an extrusion outlet of the chamber onto a substrate, the coated fiber comprising the fiber with a coating of the liquid matrix material, the substrate comprising a previously extruded coated fiber. The fiber moves in and out of the chamber at the same velocity relative to the chamber. The coating fuses with the previously extruded coated fiber and solidifies after it has fused with the previously extruded coated fiber. Relative movement is generated between the extrusion outlet and the substrate as the coated fiber is extruded from the extrusion outlet.