process such as a 3 d printing process such an additive manufacturing process may comprise selective sintering of a powdery material having particles of an average size of 1 50 microns preferably 5 30 microns during the sintering process the powdery material is completely melted through the addition of energy by means of a laser beam or an electron beam the material from which the mold is being made may be a metal or a metal alloy examples of such materials include but are not limited do titanium and titanium alloys and aluminum aluminum alloys copper and copper alloys bronze brass cobalt and chrome alloys and stainless steel in the alternative the material may be a polymeric material such as a plastic material through such a forming process it is possible to achieve a porous mold that presents well defined channels connecting the product face fp with the back face fb with the material between the channels being homogenous and at least 95 preferably 99 or 99 9 free from voids referring to fig1 a 1 d above it is noted that one or more of the tools 10 20 30 40 may be formed according to the disclosure herein it.