Historical Painting Techniques, Materials, and Studio Practice

Figure 3. Cross section if paint sample from
part if the flesh color on a sculpture in the
Nurmuizha church. The layers are as fo llows:
(1) thin pink ground, (2) main paint layer
containing lead white and ochre, (3) transpar­
ent layer containing oil, (4-8) overpaints.
Photograph by M. B. Va naga and R. Kan­
ins.

Figure 4. Cross section if paint sample from
part if the podium in the Burtnieki church.
The layers are as fo llows: (1) thin pink
ground, (2) layer of silver leaves, (3) green
layer containing cupric resinate, (4-8) over­
paints. Ph otograph by M. B. Va naga and
R. Kanins.

156

marbled columns, multicolored paintings on the panels, and blue and silver

paintings on the podium. The identities of the artists are unknown (Fig. 2).

Methods

Analysis of the pigments was carried out combining optical microscopy, mi­

crochemical tests, and emission spectroanalysis (2, 3). Media were determined

by the use of thin-layer chromatography, infrared spectroscopy, and micro­

chemical tests (4, 5, 6).

Materials and results

Te chnical analysis from paint samples was executed to reveal the original layer

of the pulpit of the Nurmuizha church. Samples were taken from the back­

ground and profiles of the pulpit's twisted columns (now black) and from the

decorative wood carvings of grapes, masks, and reliefs (now gold). The results

indicate that the ground layer consists of an unpigmented calcium carbonate

bound with an animal glue, as was shown by staining tests. In the cross section,

the ground layer is shown as a white layer with some small brown glue

particles. On a thin transparent layer in which protein has been fo und, there

is a black layer with occasional particles of a blue pigment. The few blue

particles present are transparent; a positive identification of the pigment was

impossible. Later overpaintings are executed in black, containing charcoal and

oil. The decorative vines are gilded. The underlayer is composed of calcium

carbonate and glue. In the cross section, a layer of brown hematite is visible

and the presence of glue particles was determined with staining tests. On top

of the gilding there is a layer of mordant gilding: oil pigmented with ochre

and minium, the latter probably acting as a drying agent. The bronze layer

on the pigmented oil layer was applied much later.

Samples were taken from the clothes, hair, and flesh color of one sculpture

on the pulpit (Fig. 3). The analyses showed that the gilded wrap was executed

in a water-gilding technique, while the dress itself was originally blue. The

blue layer consists oflead white and smalt with tempera as a binding medium

on a chalk-glue ground layer (7). Analysis of the samples taken suggests that

the pulpit had water-gilded, wood-carving details on a blue background. The

same blue color is also fo und in other details of the church's decoration (the

altar and the decorative ledge). Later overpaintings, however, have penetrated

the original, damaged layer, changing it and making a correct analysis difficult.

During the technical investigation of the pulpit of Burtnieki church, samples

were taken from parts that were well conserved: the background of the pulpit's

construction, the podium's decorative ledge, the decorative grapes, the roof,

and the pelican. The results of the analysis show that the pink background

contains hematite and occasional particles of calcium carbonate (CaC03) in

oil (Fig. 4). Colors from the original marbling are revealed in the background

(smalt, indigo, hematite, charcoal black, and copper resinate). Decorative ele­

ments are silvered, such as the silver leaves, which were glazed with copper

resinate over the pink underlayer (hematite, oil).

The decorative bunch of grapes is painted in a dark blue layer containing

indigo, smalt, and oil, and the green leaves are executed in a green glaze

(copper resinate, oil, gum) over silver leaf applied in an oil-based mordant

technique. The decorative details of the pulpit's baldachin have the same

preparatory ground layer as the podium. The marbling is carried out as de­

scribed above. The silvering is done using an oil mordant and subsequently

glazed. In some places the silver is covered with colorful glazes (i.e., the drops

of blood on the pelican are executed in an organic red glaze on silver). In

summary, the decorative painting of the Burtnieki church shows a rich poly­

chromy and is executed in an oil medium.

Historical Painting Techniques, Materials, and Studio Practice