In paintings from Stefan Gierowski's first, figurative creative stage, one can notice traces of a post-cubist rhythmisation of a form and simplifications borrowed from the naïve art (Gołębnik / Dovecote). Around 1957, the artist stepped into non-figurative painting, which became his main area of interest. At the same time, he stopped giving his works literary titles and from that point on, he consistently signed them with roman numerals. In the same year, the art critic Aleksander Wojciechowski described his art as “autonomous abstraction,” which seems to be the most appropriate term for the overall output of Stefan Gierowski. The emphasis on the sole phenomenon of a painting also indicated that the artist began to search for a new formula of a painted image, devoid of all content other than the effect of colour. Obraz nr I / Painting no. I was created in 1957. Gierowski started painting abstract compositions, in which the intellectual factor, manifesting itself in a clear composition, was dominated by emotions. The latter could be identified both in the subtle, sophisticated colour composition, usually monochromatic, as well as in the texturally rich surface of the canvases. Already at that time, his paintings included an announcement of the issues related to light, space, and movement, which eventually reigned in his practice. Gierowski's paintings with numbers from I to XX could be labelled as informel, a current which was at the time growing in the West. The evolution of Gierowski's art was aimed towards reinforcing the intellectual factor. In the late 1950s, when his series of silver and grey canvases came out, critics associated Gierowski's explorations with Władysław Strzemiński's theory of Unism.
Around 1960, Gierowski's works started demonstrating an inclination towards a geometric structuring of paintings. The artist was gradually discarding the emotional and intimate atmosphere. He started using a more simplified language, narrowed down the colour range, and applied the colour accents on the borders of a canvas. During that period, the surfaces of his paintings were almost Unist-like in their arrangement, which was achieved by means of subtle colour solutions. In mid-1960s, the artist came closer to explorations typical for op-art, however it was a purely formal and superficial proximity (application of value gradient and rhythmical division of the canvas area by means of lines separating different value sections in the painting). Gierowski's paintings from that period represent dynamic visions of painting's internal space, constructed out of straight, circular, or elliptical lines, superimposed on the gradations of value condensation. Space in them is treated in an illusory way. Through colour, Gierowski implies a certain spatial order in his paintings. The colours are arranged into stripes with a different hue and lucidity, which conjures the matter of the space. Lines split the painting into areas, while light connotations carry a tension. Lines in Gierowski's paintings have often been interpreted as referencing physics, they were perceived as transpositions of scientific graphs, images of shock waves, or delineations of magnetic fields. In the 1970s, Gierowski organised his canvas compositions exclusively through colour gradients, initially using pointillism, to later counterpose large areas of differently toned colour. In his paintings from the 80s, the emotional impact of colour became prominent, while Gierowski began expressing himself in a more subjective, or even spiritual manner.