A method for the preparation of a window having at least two optical states, comprising an optical device which is operable in and electrically switchable between the at least two optical states of the window, comprising - providing a first transparent substrate supporting a first electrode and a second transparent substrate supporting a second electrode , wherein each of the first electrode and the second electrode is a patterned electrode, wherein at least one predetermined resistive portion being void of any conductive material is arranged in an otherwise continuous layer of a transparent conductive material such that at least one electrically insulated segment having a predetermined shape is formed on each substrate , and - configuring an electro-optical cell including the first patterned electrode as arranged on the first transparent substrate and the second patterned electrode as arranged on the second transparent substrate and disposing between said substrates with said electrodes a medium capable of modulating light in response to an applied voltage, wherein the respective electrically insulated segments have open shapes which correspond to complementary parts of a desired pattern having at least one closed feature and which are arranged in relation with each other on the substrates and wherein the substrates are aligned with respect to one another in a manner such that an image having at least one closed feature is portrayable by the optical device in one of the optical states, wherein the substrates are aligned such that complementary edges of the respective electrically insulated segments are matched or slightly overlap and the desired closed pattern feature appears without gap, and wherein the optical device has a size of greater than 1 m 2 . - providing a first transparent substrate supporting a first electrode and a second transparent substrate supporting a second electrode , wherein each of the first electrode and the second electrode is a patterned electrode, wherein at least one predetermined resistive portion being void of any conductive material is arranged in an otherwise continuous layer of a transparent conductive material such that at least one electrically insulated segment having a predetermined shape is formed on each substrate , and - configuring an electro-optical cell including the first patterned electrode as arranged on the first transparent substrate and the second patterned electrode as arranged on the second transparent substrate and disposing between said substrates with said electrodes a medium capable of modulating light in response to an applied voltage, wherein the respective electrically insulated segments have open shapes which correspond to complementary parts of a desired pattern having at least one closed feature and which are arranged in relation with each other on the substrates and wherein the substrates are aligned with respect to one another in a manner such that an image having at least one closed feature is portrayable by the optical device in one of the optical states, wherein the substrates are aligned such that complementary edges of the respective electrically insulated segments are matched or slightly overlap and the desired closed pattern feature appears without gap, and wherein the optical device has a size of greater than 1 m 2 . <EOS>