Cultural heritage has become a keystone for comprehending our society, as it represents and reflects our origins, passions, beliefs and traditions. Furthermore, it provides fundamental information about specific temporary spaces, materials’ availability, technology, artist’s intention, and site weather conditions. Our aim was to develop a multidisciplinary approach with a main focus on investigating two Italian large-format paintings located in highly diverse environments such as the National Theater of Costa Rica. We monitored environmental conditions and quantified fungal aerial spores. Then, we determined regions of possible biodeterioration with the software MicroorganismPattern and used the software PigmentArrangement to elucidate the apparent colour of the paintings based on distribution and arrangement of the pigment crystals. Finally, we characterized eight genera of calcareous nannofossils found in the ground layers of the artwork. The former Men’s Canteen at the National Theater of Costa Rica presented a mean air temperature of 23.5 $$^{\circ }$$ ∘ C, a relative humidity of 72.7% and a concentration of CO$$_{2}$$ 2 of 570 ppm. The fungal aerial concentration was 1776 spores/m$$^{3}$$ 3 . The software MicroorganismPattern identified 32 sampling regions, out of which 11 were positive for microbial contamination. The software PigmentArrangement determined that the blue crystals (ultramarine pigment) had the shortest distances between themselves (29 $$\upmu$$ μ m). Finally, the nanofossils identified enabled us to restrict the age of the material to a biostratigraphic interval ranging from Coniacian to Maastricthian ages. By using a multidisciplinary approach we were able to explore the diptych, suggest a set of minimally invasive perspectives in tropical environments to be used worldwide and obtain key information about the artist’s artistic process, materials used along with better understand its state of conservation.

The use of analytical techniques in cultural heritage research represents an amazing multidisciplinary collaboration. In heritage studies, it is important to pay attention to authenticating, dating, and determining the origin of works of art. Three watercolors were analyzed: Paisaje con árbol, Paisaje con casa campesina and El puente, belonging to the collection of the Central Bank of Costa Rica and attributed to the national artist Fausto Pacheco Hernández. Employing multispectral imaging and innovative computational tools, we determined the state of conservation and biodeterioration of the works evaluated. By using spectroscopic techniques such as Fiber Optics Reflectance (FORS), X–Ray Fluorescense (XRF) and Scanning Electron Microscope–Energy Dispersive X–Ray (SEM–EDX) we identified and compared different pigments in the artworks. Also, we determined the creative process of the artist. Based on our results, Paisaje con árbol was the most likely, of the three paintings, to be attributed to Costa Rican artist Fausto Pacheco, followed by Paisaje con casa campesina and lastly El puente. Finally, we studied the antibacterial and antifungal properties of two of the pigments identified in the paintings (ultramarine blue and yellow ochre). Both the bacterial and fungal isolates were more susceptible to the latter. Applying these kind of studies help to increase the database on the Costa Rican artist and his historical period, providing a better understanding of creative techniques and palettes, in order to strengthen the database for future works.

Over time, cultural heritage has become a key for comprehending and developing our society at an individual and group level, as it provides fundamental information about our origins, specific temporary space, materials' availability using current technology, artist's intention, and site weather conditions. Here, we investigated the physical characteristics of an Italian large-format artwork diptych, located on the ceiling of the National Theater of Costa Rica, to evaluate its pictorial palette as well as the tropical climatological conditions and the fungal aerial spore concentration. We characterized the role of two innovative software tools, as they have direct connection with an effective microbiological sampling and description of secrets encompassed in each pictorial layer during the process of creation and intention. We further found that eight genera of calcareous nannofossils could be associated with the optical properties of the artwork and the effects that the artist wanted to portray through his creative process.

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