Series editors' preface - Wood Tools

100 Conservation of Furniture
tension to the frame with tacks. Figure 3.9
shows some examples of loose filling materials.
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 (see Figure 3.2). 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
(see Figure 3.8c).
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 (see Figure 3.8d).
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. Essential reading
on the historical development of upholstery is
provided by Beard (1997), Clabburn (1990),
Cooke (1987) and Montgomery (1984). For further
information see also Desbrow (1951),
Fowler and Cornforth (1986), Grier (1988),
Holley (1981), Kirkham et al. (1987), Milnes
(1983), Murphy (1966), Nylander (1990),
Passeri (1988), Schoeser and Dejardin (1991),
Schoeser and Rufey (1989), Thornton (1978)
and Walton (1979).
3.1.3 Technical examination
Upholstered objects are multi-media pieces
in which several trade techniques may be
represented. The skills of examination are
rarely embodied in one individual; successful
collaboration between curators, upholsterers,
conservation scientists and conservators of
upholstery, textiles, furniture, leather and plastics
is needed. A basic level of knowledge in
each area of expertise would provide a sound
vocabulary allowing for informed discussions
with these specialists and an understanding of
published material and research.
Simple analytical techniques include:
• Examination of fabrics and thread structures
• Microscopic examination to identify fibres,
fillings and pigments
• Burning tests for fibre and plastic identification
• Wet chemical spot tests for identification of
metals and leather tannins
• Solubility tests for identification of fibres
and dyes
• Staining tests for the identification of fibres,
dyes, dressings and adhesives.
More complex analytical techniques include:
• Thin layer chromatography to identify dyestuffs
• Gas chromatography to identify natural
finishes and adhesives
• Infra red spectroscopy (including Fourier
Transform Infra Red) to identify synthetic
and semi-synthetic finishes, adhesives and
fillings
• Energy dispersive X-radiography for the
identification of metals in threads, finishes
and hardware.
The application of these techniques to specific
materials is further discussed below. Details of
the techniques are provided by Sibilia (1996).
3.2 Top surface/simple structures
Top coverings may be loosely classified as fabrics,
skins or plastics.