A painting method of a surface of a wall or substrate comprising the following steps: A) providing a painting device comprising: - a handle with a longitudinal axis suitable for being held by an operator, - a supporting rod connected to the handle, and - a cylindrical roller rotatably mounted on the supporting rod so as to rotate about an axis of rotation orthogonal to the axis of the handle; said roller comprising an outer surface and a plurality of projections that project radially from said outer surface; wherein said projections of the roller are shaped like a truncated pyramid with square base, which narrows as one moves away from the axis of rotation; said projections being regularly spaced along rows that extend in parallel direction to said axis and columns that extend circumferentially to the roller; B) applying a layer of paint to a surface of a wall or substrate, and C) using the painting device by rolling the roller over said layer of paint when the layer of paint is still fresh, so that the projections compress and reduce the thickness of the layer of fresh paint, leaving prints with an irregular contour and a different shade of color with respect to a color of the layer of fresh paint that has not been in contact with said projections of the roller, so that the painted surface has an appearance similar to that of a fabric used for jute bags. A) providing a painting device comprising: - a handle with a longitudinal axis suitable for being held by an operator, - a supporting rod connected to the handle, and - a cylindrical roller rotatably mounted on the supporting rod so as to rotate about an axis of rotation orthogonal to the axis of the handle; said roller comprising an outer surface and a plurality of projections that project radially from said outer surface; wherein said projections of the roller are shaped like a truncated pyramid with square base, which narrows as one moves away from the axis of rotation; said projections being regularly spaced along rows that extend in parallel direction to said axis and columns that extend circumferentially to the roller; - a handle with a longitudinal axis suitable for being held by an operator, - a supporting rod connected to the handle, and - a cylindrical roller rotatably mounted on the supporting rod so as to rotate about an axis of rotation orthogonal to the axis of the handle; said roller comprising an outer surface and a plurality of projections that project radially from said outer surface; wherein said projections of the roller are shaped like a truncated pyramid with square base, which narrows as one moves away from the axis of rotation; said projections being regularly spaced along rows that extend in parallel direction to said axis and columns that extend circumferentially to the roller; B) applying a layer of paint to a surface of a wall or substrate, and C) using the painting device by rolling the roller over said layer of paint when the layer of paint is still fresh, so that the projections compress and reduce the thickness of the layer of fresh paint, leaving prints with an irregular contour and a different shade of color with respect to a color of the layer of fresh paint that has not been in contact with said projections of the roller, so that the painted surface has an appearance similar to that of a fabric used for jute bags.