Historical Painting Techniques, Materials, and Studio Practice

Figure 2. Detail IR-refiectogram from The
Twenty-ninth King of Shambhala, showing
the color code ngo kya on the leg of a
goat. Denman Waldo Ross Collection, Museum
if Fine Arts, Boston (06. 335).
The notation ngo (sngo), found on twenty-two Shambhala paintings, means
light blue or sky blue (9). Ngo was used for sashes, linings of garments, jewels,
nimbuses, rock crags, and lotus petals. Samples of this color taken from four
paintings were identified as a mixture of azurite and kaolin. Further whitening
of this pigment is indicated by the notation ngo kya (sngo skya) and is used
to depict the color for water, a goat, the sky, and the skin color of a king (10,
11, 12). This notation is shown in Figure 2. The additional character kya
indicates that more than 50 percent of the color mixture is white. An actual
quantitative measurement is difficult to carry out; however, one XRD pattern
of a ngo kya sample indicated a higher kaolin:azurite ratio than an XRD
pattern taken from a ngo sample.
Greens. Basic green is denoted by pa (spang), an abbreviation fo r the Tibetan
word meaning malachite (13). Pa, observed on all twenty-three Shambhala
paintings, is used for rock crags, land masses, garments, jewels, and foliage.
The green pigment was identified by FTIR and XRD in four samples as a
mixture of malachite and brochantite. Since brochantite is associated with
malachite deposits, the combination is probably a natural one (14). The mined
source for malachite in Tibet was probably the same as previously mentioned
for azurite (15).
A mixed green was found on twenty-one Shambhala paintings. Jackson and
Jackson describe a "compounded green" (sbyar ljang) derived from a mixture
of orpiment and indigo (16). The notation uncovered is jang, occasionally
written 'jang, and is used for nimbuses, mountains, lotus centers, and leaves.
The color varies from deep blue to aqua to yellowish green. Five samples
taken from five paintings were examined by FTIR, XRD, EPMA, and PLM.
Examination of two of the five dispersed pigment slides revealed a mixture
of realgar and clay. Two other slides contained a mixture of realgar, orpiment,
and clay. The fifth contained a mixture of only orpiment and clay. Indigo,
tentatively identified in three dispersed pigment slides, was positively identified
by FTIR in one of the samples. UV Ivis spectrophotometry analysis of
these samples is planned fo r the fu ture in hopes of definitively identifYing
indigo. The chromatic differences found in the samples may be due to the
fugitive nature of the indigo or to the discoloration of either realgar or orpimento
Indigo may fade when applied thinly, especially when exposed to
sunlight (17). Although each sample appears to be slightly different, it is
thought that the original ingredients were the same: namely, clay, orpimentl
realgar, and indigo. The notation jang kya mang skya), meaning light green,
was revealed on two Shambhala paintings for decorative elements of a king's
throne, clouds, and land masses (18). The color notation jang nag jang nag),
meaning dark green, is documented on four Shambhala paintings and is used
for leaves and land masses (19). The paint covering this notation as well as
the jang kya has yet to be sampled.
Yellow. Color notations fo r yellow (ser po) were documented on nineteen
Shambhala paintings. The notations are actually written as one of the following
three: se, ser, or sare. Se is the most abbreviated and sare is a misspelling,
perhaps to facilitate writing. The pigment mixture for these notations was
consistently fo und to contain orpiment mixed with kaolin and a small amount
of red lead. Five samples from four paintings were taken from areas with sare.
FTIR analyses indicate a kaolin-type clay, similar to the spectrum described
for ka. Examination of four samples by EPMA identified silicon, aluminum,
magnesium, and lead, as well as minor amounts of calcium, iron, and arsenic.
PLM revealed clay particles mixed with spherical aggregates of red lead and
fine to medium particles of orpiment. On one slide several large particles of
realgar were identified. Realgar (arsenic disulfide) is often fo und in natural
deposits with orpiment (arsenic trisulfide). Large deposits of orpiment exist
near Chamdo in eastern Tibet and in the Yunnan Province of China (20,
21).
One of the samples taken from the area marked se was nearly colorless. Surface
elemental analysis by XRF identified arsenic as a major element, yet neither
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Historical Painting Techniques, Materials, and Studio Practice