Investigation of Chromatic Parameters of Some Samples from Constanta Casino ^†

Cultural monuments are subject to a degrading phenomenon induced by several factors, such as pollution, temperature, and humidity variations [1,2]. In the last years, several studies have been carried out in order to investigate the main factors involved in the degradation of art components and historical monuments. An example of a historical monument is Constanta Casino, which was built in 1909 and opened in 1910. It was designed by Swiss-Romanian architect Daniel Renard in the Art Nouveau style [3]. Although a landmark of the Black Sea shore, the building was abandoned from 2000s, and is currently in a very bad shape.

This study presents the archaeometric investigation of stained-glass window samples collected from Constanta Casino (named P9–P19). In order to understand the manufacturing and weathering/deterioration processes of these artifacts, color measurements were recorded. The differences in L*, a*, and b* and the total color differences ΔE*ab were calculated. The CIELab (CIE 1986) chromatic parameters were chosen for the study, i.e., chromatic coordinates a* and b*, with the following significance: coordinate a* ranges in value from +60 (red) to −60 (green) and b* from +60 (yellow) to −60 (blue).

The chromaticity coordinates presented in Figure 1 indicate the change in color of the samples. It can be observed that all the positive Δa values suggest the presence of red pigments, while all the positive Δb values suggest the presence of yellow pigments in the samples. P9–P13, P16, P18, and P19 show different tones of green shades, and P14, P15, and P17 show dark tones: black, blue and brown.

These colorimetric determinations on stained-glass windows demonstrate the presence of some pigments with different shades in the green-red-yellow area, useful for further conservation procedures.