Mucha produced a flurry of paintings, posters, advertisements, and book illustrations, as well as designs for jewelry, carpets, wallpaper, and theatre sets in what was termed initially The Mucha Style but became known as Art Nouveau (French for "new art"). Mucha's works frequently featured beautiful young women in flowing, vaguely Neoclassical-looking robes, often surrounded by lush flowers which sometimes formed halos behind their heads. In contrast with contemporary poster makers he used pale pastel colors.
Mucha's style was given international exposure by the 1900 Universal Exhibition in Paris, of which Mucha said, "I think [the Exposition Universelle] made some contribution toward bringing aesthetic values into arts and crafts."
He decorated the Bosnia and Herzegovina Pavilion and collaborated with decorating the Austrian Pavilion. His Art Nouveau style was often imitated. The Art Nouveau style however, was one that Mucha attempted to disassociate himself from throughout his life; he always insisted that rather than maintaining any fashionable stylistic form, his paintings were entirely a product of himself and Czech art. He declared that art existed only to communicate a spiritual message, and nothing more; hence his frustration at the fame he gained by his commercial art, when he most wanted to concentrate on more artistic projects.