Fathi is widely recognized for expanding the tradition of calligraphy and pushing it to new heights. Her works are inspired by American Abstract Expressionists and Iranian and Middle Eastern modernists, who pioneered the use of the written word as a pictorial element in the late 1950s and early 1960s. Technically brilliant, she has developed a new visual language, which reconciles the ancient with the contemporary. Fathi's interest in calligraphy derives from the medium's intention to match the visual beauty of a text with its content. Instead of communicating with words, she pushes the gestural qualities of calligraphy beyond language, into abstraction. Her works repeat forms, creating a meditative quality.

Fathi's works are housed in the collections of the Metropolitan Museum, New York; the Asian Civilization's Museum, Singapore; the Brighton & Hove Museum, England; the British Museum, London; the Carnegie Mellon University, Doha, Qatar; the Museum of Islamic Art, Malaysia; the Devi Art Foundation, New Delhi, India ; the Denver Art Museum, Denver, USA ; the World Bank in Washington DC and the Farjam Foundation Dubai, UAE.