A decoration line including a conveyor of the products on which to apply the enamel, at least a first enamelling machine of the spray type actuated by piezoelectric-driven nozzles suitable for applying, on the products transiting on the conveyor, at least one first substantially full layer of enamel of the vitreous type in suspension in liquid suspending agent suitable for being processed in a digital decorative system for creating base or a covering layer on the products and at least a second enamelling machine, positioned downstream of said first machine, of the spray type actuated by piezoelectric-driven nozzles suitable for applying, on the products transiting on the conveyor, at least a second substantially discontinuous layer of enamel of the vitreous or pigmented type in suspension in liquid suspending agent suitable for being processed in a digital decorative system for creating decoration or finishing effects on the products.