After studying in Zurich, Karlsruhe and London Weber-Lipsi moved to Paris in 1926 where she met her future husband, the sculptor Morice Lipsi. Together, they lived in the Parisian artists' residency La Ruche where they were in close artistic exchange with artists such as Guillaume Apollinaire and Marc Chagall. Hildegard Weber-Lipsi also led a lifelong friendship with Sonia Delaunay, with whom she exhibited numerous times at the Salon des Réalités Nouvelles. The beginning of World War II forced the Weber-Lipsi couple to flee Paris separately. Morice fled to the Charente while Hildegard moved back to Zurich. After the war, they continued living and working in Zurich and Paris.
The paintings by Hildegard Weber-Lipsi reveal a curious and vigorous artist; her work evolved from dark tones in the 1950s to a more colourful and radiant palette in her later life. Her artworks are the result of an experimental, painterly dialectic in the search for the proper artistic expression. The flowing, sometimes nervous brushstrokes merge with an apparent lightness and spontaneity into expressive compositions. In the process, Weber-Lipsi developed an extraordinary characteristic colour palette, consisting of light pastel shades combined with strong, pure colour accents. She increasingly rejected the earthy, dark tones of the Paris School. Especially the vivid festivals in Japan, where she travelled for the first time in 1963, left a strong impression on her and influenced her compositions to become more intense and colourful.
Compared to the more famous representants of Parisian Informalism, like Wols, Jean Fautrier, or Hans Hartung, whose artworks are predominantly loud, obtrusive, and rough, Weber-Lipsis work appears more humble refined and subtle. In a unique way, she combined pulsating colour fields (Colour Field Painting) with dynamic brushstrokes (Action Painting) to create poetic, gestural abstractions.
As it was usual in informalist painting, Weber-Lipsi never based her works on pre-drawn compositions, but rather relied on her intuition. Whether the outcome matched the sought-after form depended on this process of automatism (écriture automatique): "All that I paint is, at first, complex and turns lighter, once I find the strength to do so. I paint and I don't know what is going to happen but once I recognize it, it makes me happy and if it succeeds, I am grateful, because that success hangs by a thread."
Weber-Lipsi exhibited her works for the first time in Paris in the Salon d'Automne in 1929 and several times in the Salon des Réalités Nouvelles (1962 – 1969). International exhibitions followed, e.g., in Zurich, Basel, Ascona, Paris, Frankfurt am Main, and Tokyo. Her paintings are represented in private collections in Switzerland, France, Germany, Italy, and Japan.