A process for producing a metal article containing at least 10% interconnected porosity, using a preform (11), comprising: mixing an organic binder, a wetting agent and a granular material, to obtain a mouldable paste that combines 10 vol. pct. or more of said granular material, said material dissolving easily in a liquid solvent; shaping the paste into an aerated preform and providing an open pore space to be infiltrated by the metal or alloy; evaporating said wetting agent and baking said preform to a temperature sufficient to degrade the binder and create a network of interconnected open porosity in the preform; filling said open pore space with the liquid metal or alloy. All or part of the baked preform can be easily leached by a liquid solvent through the network of fine pores.