He worked mainly in oils and pastels, using subtle colour harmonies and lively brush strokes to bring out the natural beauty of ordinary subjects.
Back in Zagreb, he kept in contact with these founders of the Earth Group (Grupa Zemlja), whose ideological views were bringing current social problems and the grim reality of rural life into contemporary art.
[3] Immediately following his graduation, Kovačević received a grant from the state government (Sava Banovina)[2] and spent a year (1930/31) in Paris studying fresco painting.
[3] During this year, Kovačević did not get involved in painterly or bohemian circles, but joined the international left-wing group around Le Monde, which held meetings and lectures about modern art.
His visits to the studio of Amédée Ozenfant, the founder of Purism, made a strong impression on him, along with the works of Giotto, Fra Angelico and Velasquez.
[3] Early on, he developed his own distinctive style, influenced by the social ideologies of the Zemlja group, and the reaction against depicting volume in the form.
However, in contrast to the wider scenes of rural hardship produced by other members of the group, Kovačević conveyed his message using the small details that told of a very basic way of life.
The anxieties of war showed in the dramatic painting "Začretje Castle" (1941) with its moody colour palette and ordered composition.
His "Self-Portrait" of 1948 was a personal vision in which he reduced the design to its essentials and established a muted colour palette in predominantly soft blues.
These paintings showed more vibrancy, with richer colour schemes and geometrical structures, building volumes with broad planes.
In tones of blue and brown, his beautifully designed compositions are perfectly balanced, and have been described by Grgo Gamulin as masterpieces of Croatian art.
One of the high points of the series is the tapestry "Roofs", created in 1969, into which all his earlier ideas were woven using a rich, harmonious blend of colours.
[citation needed] Edo Kovačević's later work was inspired by the landscapes of the Zagreb foothills and Hrvatsko zagorje, capturing nature in all its different weather and seasons.
Using oils or more expressively, pastels, he modified his colour palette subtly to interpret the atmospheric conditions from warm summer sunshine, soft spring rains or dense winter fog.