Stella angolata presents a commanding geometric field in which five angular ray-forms radiate outward from a luminous white pentagonal void at the composition's center. Each ray is built from tightly packed black and white stripes that bend sharply at their midpoints, generating an insistent sense of rotation and spatial tension. The stripes do not merely describe form but actively destabilize the picture plane, causing the eye to oscillate between figure and ground, flatness and illusory depth. This perceptual ambiguity is the work's primary subject, and Grignani engineers it with the precision of a technician and the sensibility of a poet. What distinguishes this particular work from Grignani's purely monochromatic investigations is the subtle but decisive introduction of color within one of the five rays. Three stripes in warm orange, cadmium yellow, and soft lavender interrupt the black and white rhythm, inserted with an almost clinical restraint. Rather than decorating the composition, these chromatic accents heighten the optical vibration of the surrounding passages and draw the viewer's attention to the structural logic of the whole. The color reads simultaneously as anomaly and confirmation, as if Grignani is testing the limits of his own system and finding it capable of absorbing surprise without losing coherence. Executed in tempera on Schoeller cardboard, a support favored for its dimensional stability and smooth receptive surface, the work belongs to a mature phase of Grignani's practice in which scale and medium were subordinated entirely to conceptual and perceptual aims. At just 22.5 by 22.5 centimeters, Stella angolata achieves an intimacy that rewards sustained, close attention, the small format concentrating the optical energy rather than dispersing it across a large field. Grignani's career as a graphic designer and theorist of visual perception informed every aspect of his art, and this work encapsulates the ambition that ran through both pursuits, namely the conviction that geometry could be made to speak directly to the nervous system. For collectors, it represents a precise and rare example of Italian Op Art at its most rigorous, a work that continues to perform its intended effects with undiminished authority more than three decades after its creation.