The sling seat is one of the simpler types and has been admitted since the kickoff of upholstery in ancient times. It consists of a single layer of sturdy material not unlike as leather stretched across and attached to a ( oftentimes wooden ) framework by means of tacks or dome headed nails. This type of seat was used on folding chairs and stools and was often provided with cushions for larger comfort. Some sling style seats were quilted, an early appearance of layered upholstery. The seat and back of a late sixteenth century sample in the collection of the Metropolitan Museum of Art, New York ( 41. 100. 321 ) consists of a layer of leather and a layer of linen stitched well-organized in a scale design in which the singular scales are padded out with hair awash through holes in the linen layer.
The introductory fixed upholstery types, that is upholstery which is attached to a rigid reasonably than a folding structure, are the clean dome and boxed edge types of the late sixteenth and early seventeenth centuries. These consist presently of pin, or boxed edge, cushions gigantic with one type of loose packing homologous as ill-favored hair or down, attached to a wooden framework by means of tacks and dome - headed nails. Due to dearth of structure across the base and sides of the upholstered seat, both of these quiet types easily became grungy during exertion. The introduction of inadequate bands of coarsely woven linen or hemp stretched across, and tacked to, the seat base provided a sturdier foundation to gate the weight of the sitter and the overlying layers of upholstery. Early attempts to prolong an aligned tidiness of upholstery were achieved with a configuration of quilting, though far structures were not possible using this technique. Shallow tufting, an eighteenth century practice, served to hold fills in place as stitches went through all upholstery layers. These were sometimes purely functional and sometimes more decorative.
By the middle of the eighteenth century, upholstery structures were quite technically advanced and more complex than ever before. They consisted of multiple layers of fillings of different densities separated from each other and contained by various types of woven cloths. Full advantage could be taken of the different qualities of different fills. Denser, less resilient, fills were used near the base of the structure with less dense and more resilient fills closer to the top cover providing more comfort for the sitter. An example can be seen in the wing chairs of the mid - eighteenth century. The rounded edges of the seat rail and inner wings were formed with densely packed straw or dried grass encased in narrow strips of linen and hemp cloth tacked under tension to form a firm roll - edge that did not distort during use or from the tension of the overlying layers ( particularly leather ). The well created in the middle of the seat and wings was fitted with a less dense filling for purposes of comfort. The loose filling was evenly distributed and held with very large stitching thread passed through a foundation of stretched linen and webbing, and then covered ( including the roll edge ) with a filling cover, held under tension to the frame with tacks. The next development was the stitched edge, in which two basic types of stitches were used, blind stitch to build the depth of the seat and top stitch to bring the edge outwards and form the roll edge. These stitches enabled the shape of the edge to be controlled during manufacture and maintained during use. By the late eighteenth or early nineteenth century all of these developments, and variations, were being used both alone and in combination with each other.
The major innovation in the nineteenth century was the use of coiled springs. Individual coil springs were used in groups on the seat frame. These were held together under compression on the webbed base with cords and stitching to form a unit. The sprung unit was used in combination with various stitched layered fills forming deep stuffed upholstery. In comparison to previous upholstery structures, the sprung seat was extremely comfortable.
Buttoning is a nineteenth century development, not to be confused with eighteenth century tufting. It consists of a textile covered deep filling laid onto a tensioned cloth base on the frame. The filling is compressed at regular intervals by stitching through all the upholstery layers and knotting off the thread under tension to buttons forming a pattern of deep stuffed padded pockets. An exaggerated version of this technique is known as deep buttoning.
By the twentieth century, technology made it possible to manufacture the upholstery for a chair in the form of a single preformed foam unit with variations in density created by cavities moulded into the foam. Spring units, rubberized webs and tension springs are all twentieth century developments of earlier upholstery structural components rather than true innovations but each has had an effect on furniture design.
