"What is essential is invisible to the eye," said Antoine de Saint-Exupéry, in his Little Prince. The French artist Orsoleone breaks down the word to use as the title of the exhibition, highly recommended, The essence-ciel open until 16 December at the Institut Français - Center Saint-Louis Largo Toniolo in Rome- The essence-ciel, translated into Italian, essence - the sky; Furthermore, in French, the two words together sound like the only word essentiel, that is essential. Element that unites the 75 works gathered here, is a color universe which shows the indomitable fantasy artist Orsoleone. His stage name comes from the bear,