Real curved walls are rarely true arcs. The SB-150 is drawn from a survey of the actual wall - in the standard reference, a curve that tightens from about 118 in (300 cm) to 59 in (150 cm) radius over a developed length of 87 in (220 cm) - and keeps the seat front parallel to the back throughout.
How it is resolved. The frame is built on a full-size template plotted from your survey offsets. The seat depth is held constant at 22 in (56 cm) along the curve, so the seat front is an offset of the wall line, not a separate guess. Back upholstery runs continuously, and the metal top trim is bent to the same template.
Specifying it. Provide a radius schedule or, more reliably, offsets measured perpendicular to a chord at regular intervals (every 12 in / 300 mm is usually enough). Note wall construction for fixing. Tight radii limit fabric choice: stiff vinyls and heavily backed cloths can wrinkle on curves under about 36 in (90 cm) radius, so we will comment on the selected COM.
Where it works. Bay windows, adaptive-reuse buildings, round towers and feature curves in hotel restaurants where a standard radius banquette would leave gaps.
