Abstract: A method and system of modifying a substrate using a plasma are described comprising providing a first electrode and a second electrode; arranging the substrate such that a portion of the substrate is between the electrodes; supplying a voltage to at least one of the electrodes so as to create a plasma discharge between the electrodes which contacts at least said portion of the substrate, moving either the substrate and/or said second electrode such that said substrate and said second electrode are being linearly displaced relative to each other along an axis of linear displacement during said movement; and wherein said second electrode is arranged relative to said axis of linear displacement such that said linear movement causes a first section of the portion of substrate to have a greater residence time between the electrodes during said linear displacement than a second section of said portion of the substrate.

Abstract: A method of modifying a substrate using a plasma comprises providing a first electrode and a second electrode; arranging the substrate such that only a portion of the substrate is between the electrodes; and rotating either the substrate or at least one of the electrodes about an axis so as to cause different portions of the substrate to pass between the electrodes during the rotation. A voltage is supplied to at least one of the electrodes so as to create a plasma discharge between the electrodes which contacts at least the portions of the substrate that pass between the electrodes. The electrodes and the substrate are arranged such that the rotating causes the speed of transit of the substrate portion between the electrodes to vary in a radial direction away from the axis of rotation and the rate that the plasma discharge modifies the substrate varies across the substrate.

Abstract: A label that changes appearance with time is disclosed. The label comprises a first layer that has different permeabilities to a gas in different lateral areas of the label and which comprises a substance that changes colour when in contact with the gas. The substance is arranged within the label such that the gas permeates across the thickness of the layer at different rates in different lateral areas so as to cause the substance to change colour at different rates in said different areas. Another label that changes appearance with time is disclosed that allows ink to permeate to its surface at different rates in different lateral areas.

Abstract: A method of modifying a substrate using a plasma comprises providing a first electrode and a second electrode; arranging the substrate such that only a portion of the substrate is between the electrodes; and rotating either the substrate or at least one of the electrodes about an axis so as to cause different portions of the substrate to pass between the electrodes during the rotation. A voltage is supplied to at least one of the electrodes so as to create a plasma discharge between the electrodes which contacts at least the portions of the substrate that pass between the electrodes. The electrodes and the substrate are arranged such that the rotating causes the speed of transit of the substrate portion between the electrodes to vary in a radial direction away from the axis of rotation and the rate that the plasma discharge modifies the substrate varies across the substrate.