Throughout their long and productive career, the Vignellis put these principles into practice. From 1957 – 1960, after training as architects in Italy, the couple went to the US on fellowships. Here it became clear that their mission was “Better design for a better world.” The Saratoga furniture and Heller's melamine stacking dinnerware both showcase a strict and clear design style.

The Vignellis settled permanently in the US and in 1965 co-founded the American branch of Unimark International. This design consultancy created distinctive corporate identities for companies such as American Airlines, Ford, Knoll International, the Transit Authorities of New York City and Washington, DC – and for Heller.

In 1971, the Vignellis started their own office in New York called Vignelli Associates. They worked on a variety of projects that were impressive in their size and design.

These include graphic design programs for the United States National Park Service, Bloomingdales, Lancia, Fratelli Rossetti, The Guggenheim, the Salone del Mobile, and Benetton; showrooms for Poltrona Frau, Steelcase, Italcenter, Hauserman, and Artemide, interiors for the Minneapolis Museum of Fine Arts, Joseph Magnin, The United States Postal Service, and Saint Peter’s Church in Manhattan; exhibits for the Louvre and BMW; furniture such as the Handkerchief chair (Knoll, 1982-1987), products for the Ciga hotels and Heller, and books for many publishers.

Based on the motto, “If you can’t find it, design it,” the Vignellis also designed their own clothing line.