After finishing at the School of Applied Art in Zurich, Tissi joined a design consultancy, though this job didn't offer much creative challenge. She started looking for a new place and soon met designer Sigi Odermatt, known for his bold style and rebellious attitude towards industry rules. He had his own studio and hired Tissi as an apprentice. After a decade, she became a business partner. In 1974, Rosmarie Tissi created Sinaloa—a logotype style typeface with strong geometric forms. Each character has a striped stroke which helps keep the letters legible and gives the typeface its eye-catching appearance. “I have always reduced my design to the essential, employed only few elements and played with the proportions and the empty spaces,” Rosmarie Tissi once said. Rosmarie Tissi's style has been evolving throughout her career: from the pure functionality of grid-based Modernist design to a very individualistic aesthetic with vivid colors, peculiar proportions and experimental layouts.