Abstract: A chair includes a base, a chair control and tilt mechanism, a shell assembly and a cushion assembly. The shell assembly includes a seat shell fixed to the base and a separate back shell. The back shell and seat shell are interconnected by a mechanical hinge. The hinge includes a pair of tabs on the back shell received in sockets defined by the seat shell. The tabs are retained in the sockets by the chair base. Back supports or chair arms have ends operatively connected to the tilt mechanism. Opposite ends of the arms are secured to the seat back to support and guide the back during tilting movement. The cushion assembly includes a molded foam member having a fabric or other upholstery material joined thereto. The back shell includes an integral, hinged upholstery flap. The fabric of the cushion assembly is folded over and joined to the flap. The flap is folded and operatively connected to a rear surface of the back shell. The seat shell includes another integral upholstery attachment flap.