From 1921 to 1926, he attended the School of Fine Arts in Geneva as well as the School of Industrial Arts. He studied sculpture, then also devoted himself to engraving, taking his inspiration from the technique of Japanese prints to develop, from 1924, a woodcutting process that allowed him to print subtle gradations of color. He engraved up to fourteen pear tree plates (one per color) to find the chromatic richness of a study of Ophrys fly. The artist's body of work, of a remarkable stylistic continuity, is characterized by a great profusion, regrouping no less than 30'000 drawings and 2'500 watercolors, to which one must add several hundred sculptures. As for engraving, he printed his last subject at the age of eighty-seven, thus constituting a collection of more than 1,000 pieces.
"Each of my engravings is a music: 7, 10, 12 tones, each of which has its precise flavor, which have their intervals and which I weave, interweave and superimpose. When I engraved a flock of geese emerging from the fog, I consciously made a kind of counterpoint: dark birds above, light and faded below, on a sky clearing up from below. Oil painting, rich, complex, a bit heavy and confusing, is to printmaking what the piano is to the harpsichord."
The complementary relationships between nature and human civilization are at the heart of Robert Hainard's work, which conceives art, science and philosophy as a whole. The work is inseparable from the artist's thoughts and existential preoccupations, which are particularly evident in works such as Bouvreuil, Loup dans la pénombre, L'éclair and Les escargots amoureux. "This engraving smells of earth": a compliment he was particularly fond of, as it seemed to reveal exactly what he had wanted to express. Drawing what one sees and not what one knows was the guiding principle of his work. Inspired in particular by the influence of parietal art, the drawing all in delicacy of Albrecht Dürer or the muscular force of the sculptures of Rodin.
"Like any painter, I am eager for images. I enjoy shapes and colors and am no more insensitive than anyone else to purely plastic qualities. I admire masterpieces and they immediately arouse my desire to do the same. Renoir is not wrong when he says that one becomes a painter by seeing painting, not nature. Egyptian sculpture revealed to me the fullness and simplicity of form, Greek sculpture its simple and subtle complexity, Rodin its organic and moving power. All that I had felt confusedly became clear in front of the works of art. In front of Hodler, I felt in possession of his intellectual and muscular vigor, I saw through the limpid eye of Hans Berger. I do not speak about my father because I had seen him in front of nature, that I felt too much his extension to be a revelation. I was convinced that these painters had taught me how to see, that they had made the universe comprehensible to me and that I would take it on my next outing. But learning to paint is above all becoming aware of one's visual sensations."
In 1953, he exhibited Nuits d'hiver au bord du Rhône at the Cabinet des estampes in Geneva, in praise of the otter and the still free river. The result of thirty nights of hunting, this masterly suite accompanied by handwritten texts is composed of forty-one prints engraved over fifteen years. This fidelity and constancy which characterize his work have regularly led him on the same paths, thus conferring a kind of timelessness to his works.
Concerned about the destructive relationship between man and the natural world, Robert Hainard published Et la nature? Reflections of a painter. This fundamental text places him among the first philosophers of ecological thought in the French language. He also published his field observations in Les mammifères sauvages d'Europe, a reference work for naturalists. This scientific and philosophical activity will be honored in 1969 by the award of a doctorate honoris causa in sciences from the University of Geneva and his writings will also be rewarded by the Prize of the International Academy of Philosophy of Art (Corfu).