Osvaldo Borsani office chairs

These Modus office chairs, conceived in the 1970s by Italian designer Osvaldo Borsani and produced by Tecno, embody a seamless blend of ergonomic precision and sculptural form. Each chair’s shell is molded from high-gloss red thermoplastic, its crisp edges and smooth contours defining a gently reclined backrest that flows into a slightly concave seat basin. The vivid red finish remains remarkably even, showing only faint surface scuffs at contact points—evidence of careful, long-term use without detracting from the shell’s bright, glossy presence.

Beneath the plastic shell, a five-star base of die-cast polished aluminum supports the chair with both strength and visual lightness. Each spoke tapers gracefully before terminating in a black nylon caster, enabling effortless mobility across office floors. A central column houses a height-adjustment mechanism, allowing the seated height to vary between 45 and 58 centimeters. The adjustment lever operates smoothly, its internal gas piston retaining full responsiveness despite decades of operation.

The seating surfaces have been newly upholstered in tightly woven black wool, creating a tactile counterpoint to the hard plastic shell. This dark fabric contrasts sharply with the red exterior, lending depth and comfort. The wool wraps neatly around the shell’s perimeter and over the built-in arm supports—slender black-enameled steel extensions that integrate into the shell’s profile with minimal visual interruption. The steel arm frames show only the slightest patina, their textured black finish intact.

Osvaldo Borsani (1911–1985), co-founder of Tecno in 1953, championed a rationalist approach that married engineering rigor to refined form. His Modus series exemplifies this philosophy: the chairs are modular, stackable, and designed for adaptability within dynamic work environments. Tecno’s pioneering spirit in office systems is evident in the precision of the injection-molded shell, the reliable mechanics of the height-adjustment, and the integrated comfort solutions such as the wool upholstery.

In very good vintage condition, these Modus chairs remain structurally sound. The plastic shells retain their original gloss, with only minimal abrasions. The aluminum bases show no corrosion, and the casters roll without hitch. Newly replaced wool upholstery is free from wear, while the leather-lined underside of the seat still bears the Tecno label, confirming their provenance. As both functional office seating and sculptural design objects, these Modus chairs stand as enduring examples of 1970s Italian modernism.