The invention relates to a method of forming a 3-dimensional solid object, comprising the steps: a) cold spraying one or more metallic powder to form a solid three dimensional item; b) thermally sintering the item such that a portion of the sprayed powder liquefies and reduces spaces between, and/or non-adhesion of, one or more solid portions of the item; and c) causing or allowing the portion of the sprayed powder that liquefied on heating, to become solid.