The Technique of FURNITURE MAKING
Seating and upholstery
CHAIRS General note
Chairs of compound curvature and subtle shaping require the application of special skills. and in many richly ornamented traditional examples the designer prepared his sketches, leaving it to the actual maker to choose the wood and methods of jointing. As it is difficult. if not at times impossible, to plot all the curves of an elaborate chair in two-dimensional drawings only, the final result was dependent in great measure on the skill and sensitivity of the individual craftsman, and such chairs were highly expensive to manufacture, requiring the wasteful use of heavy wood sections which were rough shaped, jointed and assembled and then sculptured and carved, using special chair - makers' tools. Modern designs employ straight sectioned stock wherever possible, and steam bending or laminating for curved work, thereby effecting considerable economies in both time and materials. Such chairs are relatively simple to make, and do not require the same measure of special skill.
Chair sizes
Much research has been done into the principles or restful sitting, but while it should be possible to construct the perfect seating medium for any particular user, the average chair is designed for unseen customers, male or female, tall or short, fat or thin. Thus careful calculations based on the law of averages should be approached with caution. For instance, the standard height of a table-top, now usually accepted as 29 in (735 mm), calls for a chair seat height of 17 in (430 mm) to 17 1/2 in (440 mm), but this is still too high for many people, and too low for some. What is badly needed, and will no doubt be evolved at some future date, are tables and chairs which can be adjusted at a touch to any individual requirement. In the meantime the measurements given below must be regarded as guidelines only.
Generally speaking the backward slope of the seat should not produce a knee angle of less than 90 degrees with the feet flat to the floor, while the elbow angle at rest on the side arms should not force the shoulders up. If the back is curved then the arch of the curve should be a bare 8 in (200 mm) above the seat, and the seat should be as deep as possible but not greater than the length of the thigh measured from the fold of the knee to the back. Easy chairs should not be so low or the backward slope of the seat so great that it requires physical leverage against the arms to lift the body from the seated position, and due allowance must be made for the extent of the compression or 'bottoming' of thick foam cushions under load.