A method for producing a tube skirt for a flexible tube, said tube skirt being manufactured from a flat strip comprising a decorative film superimposed on a primary film, said primary film comprising a sealable inner layer at the lower surface of the strip, said decorative film comprising a sealable outer layer at the upper surface of the strip, said method comprising the following steps: - winding the flat strip into the form of a sleeve to shape the tube skirt; - superimposing a first side border of the strip on a second side border of the strip to form an overlapping area, the sealable inner layer of the primary film of the first side border overlapping the sealable outer layer of the decorative film of the second side border; - applying a heating temperature T2 to the inside of the tube skirt at the inner face of the overlapping area to produce the side weld of the tube skirt; - simultaneously with the application of the heating temperature T2, applying compression between the outer and inner faces of the overlapping area so as to finalize the side weld of the tube skirt, characterized in that, simultaneously with the heating temperature T2, a heating temperature T1 is applied on the outer face of the overlapping area, the heating temperature T1 being lower than the heating temperature T2, and in that the primary film comprises two stabilizing layers (11, 13) and in that the decorative film comprises a decorative layer (8, 9). said method comprising the following steps: - winding the flat strip into the form of a sleeve to shape the tube skirt; - superimposing a first side border of the strip on a second side border of the strip to form an overlapping area, the sealable inner layer of the primary film of the first side border overlapping the sealable outer layer of the decorative film of the second side border; - applying a heating temperature T2 to the inside of the tube skirt at the inner face of the overlapping area to produce the side weld of the tube skirt; - simultaneously with the application of the heating temperature T2, applying compression between the outer and inner faces of the overlapping area so as to finalize the side weld of the tube skirt, - winding the flat strip into the form of a sleeve to shape the tube skirt; - superimposing a first side border of the strip on a second side border of the strip to form an overlapping area, the sealable inner layer of the primary film of the first side border overlapping the sealable outer layer of the decorative film of the second side border; - applying a heating temperature T2 to the inside of the tube skirt at the inner face of the overlapping area to produce the side weld of the tube skirt; - simultaneously with the application of the heating temperature T2, applying compression between the outer and inner faces of the overlapping area so as to finalize the side weld of the tube skirt, characterized in that, simultaneously with the heating temperature T2, a heating temperature T1 is applied on the outer face of the overlapping area, the heating temperature T1 being lower than the heating temperature T2, and in that the primary film comprises two stabilizing layers (11, 13) and in that the decorative film comprises a decorative layer (8, 9).