Series editors' preface - Wood Tools

permanently etch the lacquer, leaving the surface
irreversibly marred by fingerprints (Figure
16.19). When handling lacquer objects, it is
essential either to wear gloves or, after
ungloved contact, to wipe down a surface with
mineral or white spirits.
16.8.3 Distinguishing Oriental lacquer
from japanning
Japanning and lacquer on furniture may appear
similar at first sight. Both are characterized by
a pigmented background that originally often
had a lustrous appearance and was frequently
decorated with raised and gilded detail.
Designs for japanned ornament were often
derived from porcelain or fanciful interpretations
from other sources. The two surfaces are
often found on the same object and lacquer
may have been restored, altered or embellished
using japanning materials and techniques.
Japanning and Oriental lacquer can
usually be distinguished on the basis of the
nature and quality of their decorative elements.
Close inspection of areas of loss or cleavage
may allow identification by revealing lower
layers. Examination under UV light,
microscopy and solvent testing can also be
used to distinguish these materials.
The imprecise nature of identification of
coatings under UV is discussed in section 13.3.
When studying a surface under UV, conservators
should bear in mind that they can only see
the uppermost layer of the object. This may
represent an original surface or merely the latest
in a long line of ‘restoration’ varnishes.
Within the context of these limitations, japanning
based on natural European resins may fluoresce
greenish-yellow or pale creamy-orange.
The appearance of Oriental lacquer under UV
varies considerably, probably as a result of the
type of lacquer used for the final coat. Thus
nashiji lacquer, which may have been applied
as the final coating over sprinkled nashiji gold
powder, may have a startlingly bright orange
auto-fluorescence. Black lacquer may exhibit a
muted or bright orange auto-fluorescence (see
Plate 2). Makie decoration may appear black
(non-fluorescent) or exhibit an orange autofluorescence.
Unaged shellac has a distinctive
bright orange auto-fluorescence. It is important
that the conservator does not mistakenly interpret
orange fluorescence on lacquer as indicat-
Conserving other materials II 761
Figure 16.20 Photomicrograph of a thin section of
Oriental lacquer viewed under visible light. The layer
structure of both ground (1) and lacquer (2) is clearly
visible
ing the presence of a shellac varnish. Under
UV the presence of non-fluorescing makie decoration
against an autofluorescent orange
background is indicative of Oriental lacquer.
Conservators may wish to confirm the presence
of a European varnish with additional analysis.
Cross-sections of seventeenth and eighteenth
century japanning executed in resin or
oil–resin varnishes will reveal a surface similar
in many ways to a painted surface. There may
be a gesso type ground, layers of autofluorescent
resin in which the pigment content is
reduced in stages and finally clear varnish on
top. Lacquer sections viewed in cross-section
will reveal ground layers below the decorative
layers (Plate 8a). Viewed under UV, Oriental
lacquer may autofluoresce bright or pale
orange (Plate 8b), or not at all. Natural resin
varnish layers added in the west may be found
autofluorescing above the lacquer (Plate 8c).
Samples viewed in thin section will reveal the
structure of the lacquer layers (Figure 16.20).
The process of mounting cross-sections producing
a thin section is illustrated in Figure
16.21.
Solvent testing has also been proposed as a
method of distinguishing japanning and
Oriental lacquer (Westmoreland, 1988). When
newly manufactured, lacquer is impervious to
water or organic solvents and reputedly loses
gloss when exposed to nitric acid (80%) or
sodium hydroxide (50%) (Nagase, 1986).
Oriental lacquer remains insoluble as it ages,
though its degradation products are soluble in
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