"In spazio rettangolare 13 quadrati" is a geometric abstraction by Antonio Calderara that demonstrates his systematic exploration of spatial relationships through the careful arrangement of thirteen squares within a rectangular field. Executed in oil on wooden panel, the work exemplifies Calderara's minimalist approach and his interest in the subtle interactions between form, color, and pictorial space. The composition reflects the artist's lifelong investigation into how simple geometric elements can generate complex visual and psychological effects through their precise placement and chromatic variations.