In the manufacture of articles, in particular slabs, of conglomerate stone material provided with a protective and/or decorative surface coating consisting of a synthetic resin, the surfaces of the article to be coated are subjected to a treatment in order to increase their surface tension to a value greater than that of the coating material to be applied subsequently.This treatment consists preferably of a Corona discharge.Particular advantages are obtained using a fluoropolymer, specifically a fluorinated polyurethane resin, as the synthetic resin of the surface coating.