1. Introduction
Around 1400, the geographical area of East Central Europe (Austria, Slovakia, Hungary, Slovenia, Croatia) was an important crossroad between political, economic, social as well as cultural and artistic currents from Northern and Southern Europe. This situation can be clearly observed through the complex style of contemporary artworks as well as in their technical execution and in the use of materials and painting procedures. The present research is centred on mural paintings in Slovakia, which provide a very good example of what was happening around 1400. It is a part of a wider project that is still going on that investigates the entire area mentioned above. Conserved artworks reveal a mixture of influences from the North—Bohemian, Hungarian, and Austrian art, as well as from the South, especially Italian Trecento, both of which are incorporated into the local style. This diverse artistic language can be appreciated in selected mural paintings from several localities in Slovakia, with a special interest on those found along the so called “Gothic road” in the area of Rožňava/Gemer: the former St. George church in Plešivec (1370-80), the church of St. Mary’s Annunciation in Chyžné (end of the 14th and beginning of the 15th centuries), and in the Evangelical church in Štitnik (beginning of the 15th century), as the best examples.
There is no direct stylistic connection among the three of them, but they all show strong Italian Trecento influence. A lot has been published about the style and history of all three monuments, especially in Slovak literature [
1,
2,
3,
4]. In Plešivec, the whole presbytery is decorated with murals, and some fragments have also been discovered in the nave. In this research, only paintings in the presbytery have been taken into consideration. They count among the best examples of gothic art in Slovakia. In the presbytery, scenes from
Christ’s childhood and
Passion are depicted, and these paintings were completed by two different painters. On the north wall, a high-quality artist strong in the Italian Trecento tradition was active (
Figure 1a), while on the south wall, a local painter of lower artistic quality was working and combining northern and southern influences (
Figure 1b). The difference in their quality can be well observed not only from their style, but also from their painting technique and modelling, as explained in the Results section. Paintings in the presbytery were partially discovered and restored in 1977–1978 [
2]; their full discovery was achieved in 2014, and the murals are being currently restored by P. Koreň.
The presbytery in Chyžné (
Figure 2) was also entirely painted with murals, with
Christ’s childhood presented on the upper layer and the twelve Apostles on the lower layer of the walls, while on the ceiling, symbols of four Evangelists and four Church fathers are depicted. In addition, some other scenes such as
Imago Pietatis or
Parabola of ten virgins can be found. In the nave, the mural paintings are not preserved. The artist shows Italian Trecento influence, especially Rimini reminiscence [
1,
5,
6], although with a strong local note. The church in Štítnik is covered with mural paintings from different periods between the 14th and the 16th centuries. In this research, the murals on the north side nave were chosen according to their style and date. On the upper layer of the north wall,
St. Barbara and
Volto Santo are presented, which were completed at the end of the 14th century by a painter with a strong Italian influence. From the same time or maybe some years earlier, paintings on the east and west walls were completed and show a large depiction of the
Crucifixion (
Figure 3a) and a beautiful Virgin Mary (
Figure 3b), which is part of the
Annunciation. On the lower layer of the north wall, a
Passion Christi (
Figure 3c) was completed at the beginning of the 15th century; the
Passion probably covered older paintings related to the
Annunciation and the
Crucifixion.
These paintings are in a bad conservation state, which makes it difficult to read and understand them. The murals from the 14th century show strong Italian Trecento influence, while those from the 15th century have a more local impact, combining Italian trecento with northern stylistic currents [
2,
4,
5]. Murals were discovered in different restoration phases between 1874 and 1914, with the most important one in taking place in 1908–1909 by I. Groh [
2].
2. Objectives
Most of the murals have already been studied from the art history point of view, as can be well observed from the existing literature ([
1,
2,
3,
4,
5,
6], with additional bibliography). Nevertheless, their material and technical aspects are not well known, but this information is as important as the study of a piece of artwork’s style is. For this, the interdisciplinary collaboration between Humanities and Natural Sciences is vital, offering much better and complete comprehension. The principal objectives of this study are therefore to obtain information on the materials and painting techniques applied in all three of the selected mural cycles. Therefore, (a) the characterization of supports (plasters), including their composition (binders and aggregates); (b) the number of layers and the application of
giornatae (daily portions of plaster limited to one scene or one figure) or
pontatae (larger horizontal stripes of fresh plaster that can cover the entire wall width); (c) the possible use of lime-wash; (d) the identification of specific pigments (organic, inorganic) and their possible degradation; (e) the identification of specific binders (organic, inorganic); (f) the sequence of the colour layers; (g) the colour modelling and brushes used (fine, thick); (h) the painting process from the preparatory work (under-drawings, incisions, pouncing, under-paintings) to the final colour modelling (shades, highlights); and (i) the painting technique (
a fresco, a secco, lime technique) are of interest in the current work.
The information obtained here offers an understanding of the materials and painting procedures applied in the chosen murals as well as their comparison to other artworks, as planned in the near future. On this basis, the coexistence of Italian Trecento features and contemporary Central-Northern influence, as stated in art-historical analyses, can be confirmed or rejected.
3. Materials and Methods
For the material analysis, invasive and non-invasive techniques were used [
7,
8,
9,
10,
11,
12,
13,
14]. The first and most important step was a precise examination with the naked eye, which was helped by a straight and ranking light. In mural paintings, it is possible to distinguish preparatory drawings, colours, colour modelling, and brush strokes; therefore, painting procedure can also be determined. On damaged areas, we could observe the number of plaster layers and their basic composition and texture, and we could sometimes also determine the use of lime wash.
Next, small samples of the colour layers and plasters used in the murals were extracted for laboratory analysis. Samples were prepared depending on the analytical technique that was chosen; most of them were embedded in resin for cross-section preparation. Cross-sections were studied under optical microscopy (OM) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). For the optical microscopy, a polarised microscope Carl Zeiss JENAPOL with coupled with a Canon EOS 6D camera were used. For SEM-EDS, a scanning electron microscop JEOL JMS-6060LA with an energy dispersive spectrometer EX-23000BU was applied, and the samples were analysed under 15 Pa pressure and 15 kV accelerating voltage. A few samples from Plešivec were analysed with another piece of equipment, environmental scanning electron microscope-energy dispersive X-ray spectrometry (ESEM-EDX) under ESEM FEI XL30 with a BSE-Detektor//SE Detektor in high-vacuum microscope mode between 5.0 × 10
−5 mbar and 3.0 × 10
−6 mbar, and these samples were previously observed with a digital optical microscope Keyence VHX-6000 with 100–1000× magnification. The optical microscopy revealed the sequence of the colour layers and the painting technique applied, sometimes facilitating optical pigment identification based on the morphology of the particles in the sample. SEM offers additional morphological characterization, as it provides higher magnifications compared to OM, while the EDS detector is able to identify the chemical elements in the analysed point or area, and therefore, the materials applied during the painting process can also be identified. Morphological characterization by OM and SEM in the case of mural cross-sections is critical for wall painting technique identification and can be conducted through microstratigraphic analysis [
12,
13,
14,
15]. For plaster composition, samples were ground into fine powder and were analysed by X-ray diffraction (XRD) using a Bruker AXS, Germany D8 Advance model. Samples were prepared in silicon-single crystal-sample trays and were measured using Bragg–Brentano geometry, Cu-Kα
1: 1.54056 Å, Cu-Kα
2: 1.54440 Å, 40 kV, 40 mA, 5–80° 2θ, and a 0.02° increment of 2 s per step (count). Although other techniques such as FTIR, Raman or GC-MS could offer important additional results, at the moment, the use of these methods is not possible.
5. Conclusions
All of the results are gathered in
Table 7. On the basis of the information gathered so far, we can conclude that from the technical as was as from the stylistical point of view, there is not much of a relationship among the three selected mural cycles in the Gemer region (Plešivec, Chyžne, Štítnik); however, they all present relatively high technical skills and show examples of
a fresco technique execution as the principal composition method.
In all three cases, the artists finished with a secco applications for last details and contours, but only in small portion, showing that they managed to carry out most of the work on fresh plaster. All of the plasters were made of lime and sand had higher or lower binder-aggregate amount and variable impurity contents.
The plaster composition supports the stylistic characterization—painters with strong Italian influence (Plešivec—north wall, Štítnik—east wall) used better quality plaster than those with more local influence (Plešivec—south wall, Chyžné, Štítnik—north wall). The palette is similar in all three churches and was made of inorganic pigments, earths, and minerals and principally comprised lime white, yellow and red ochres and iron clays, malachite, azurite, and carbon black. Many of these pigments were obtained in local mines and hills, as is the case of spherulitic malachite and ochres. However, in Chyžné, vine black was also found, while in Štítnik, a synthetic lead pigment was applied for some details, probably a secco. The principal binder was lime from the plaster; however, the artists used also lime water to mix the pigments before their application on the wall. For the a secco parts (final details and sometimes malachite and azurite layers), an organic binder must have been used, but no analyses have been made so far. Research on mural paintings is ongoing. The results presented here still have to be completed and compared to other selected monuments in Slovakia and in other related countries in the East Central Europe, in order to better understand the materials applied and that painting techniques used by the artists as well as their possible connection from the material point of view.