Striking back If you want to see what makes the 691 series unique, just look at it from behind. The steel tube that runs over the back from arm to arm lends the otherwise sober 691 a contrastingly self-assured look. The 691 is loved for its firm comfort. The sofa is fully upholstered and is available as 2, 2.5, or 3-seater and also as a fauteuil. Its striking back also enables the sofa to stand alone in a room without looking too dominating. The 691 series has been in the collection now for 25 years and was designed by what was then the Artifort Design Group in 1987. Materials Upholstery Textile or leather. Tube in the back Chrome or powder coat.