Direct printing method for printing a cover layer onto containers

A direct printing method for printing on containers with the aid of a direct printing machine, comprising printing a print layer onto the container, in a first predefined area thereof, in a first device in a first step, and applying a cover layer to the container in a second device in a second step, the cover layer being applied to a second predefined area, which comprises the first predefined area and the surface area of which is larger than that of the first predefined area, the cover layer coalescing with the printing ink in the first predefined area thus creating a first connection, the cover layer coalescing with the container in parts of the second predefined area which differ from the first predefined area thus creating a second connection, and the first and second connections being insoluble in first aqueous solutions having a pH value between 3 and 10 and easily soluble in second aqueous solutions having a pH value in a range of less than 3 and/or higher than 10, wherein the second connection between the cover layer and the container is stronger than a connection between the print layer and the container and the first connection is stronger than the connection between the print layer and the container.

A direct printing machine for printing on containers, comprising a conveyor device for conveying the containers through the printing machine along a conveying direction, a first device for applying a print layer to a first predefined area of the container and a second device for applying a cover layer to a second predefined area of the container, the first device being arranged upstream of the second device when seen in the conveying direction, wherein the second device suitable for applying the cover layer to the second predefined area, the second predefined area comprising the first predefined area and the second predefined area being larger than the first predefined area wherein: the first device applies the print layer to the container establishing a connection between the print layer and the container, the second device applies the cover layer to the print layer establishing a first connection between the cover layer and the print layer and applies the cover layer to the container establishing a second connection between the cover layer and the container; and wherein the second connection between the cover layer and the container is stronger than the connection between the print layer and the container and the first connection is stronger than the connection between the print layer and the container.