Contemporary Murals in the Street and Urban Art Field: Critical Reflections between Preventive Conservation and Restoration of Public Art

: This paper focuses on the presentation of some of the main critical reflections concerning the current debate about conservation and restoration of contemporary murals in the Street and Urban Art field. More and more, the operations thought of for this kind of wall paintings are connected to the concept of preventive conservation or some actions with the aim of reducing the future deterioration linked to the outdoor context. The idea of protecting urban and street murals arises from two principal issues: on one hand, the (not yet) official, but social, recognition of them as works of art and beloved icons in the communities—or better “testimonies which spread the values of civilization” (definition of Cultural Heritage) from the last decades of the XX century to nowadays— and, on the other hand, the necessity of finding a way to preserve their artistic messages in the ephemeral urban context. In fact, developing a correct plan for the conservation and restoration of these works of art located in the outdoor context needs to consider—more than ever—the strict relationship between their materials, their environment, and even their viewer. This fragile axiom is strictly linked to the law of the street , where all the decay processes are, often, unpredictable. At the moment, the ICR’s (The Istituto Centrale per il Restauro) research in this field is focused on a work in progress project to develop some trials and tests with innovative materials for their preservation and a common glossary to outline particular forms of damaging in murals often based on “plastic on a wall”. The final aim could be to define institutional guidelines for the preservation of urban and street contemporary mural paintings in a perspective of a “ share for care” conservative program.


Introduction: The Lessical Definitions of Street Art, Urban Art, and Public Art in the International Scenario
In the current debate, the definition of "Street art"-now far from Post-Graffiti definition but also from the Rigglerian one of 2010, where "An artwork is street art if, and only if, its material use of the street is internal to its meaning" [1]-is used in a generalized way by the critics and the art market to define a series of heterogeneous artistic manifestations, united by the desire for opposition to the prevailing cultural system and the choice to illegally perform one's works [2]. Nowadays, this definition certainly bends itself to repeated social negotiations, and it is also improperly used to define artworks realized for the gallery circuit or performed on commission in the outdoor street context, which is, instead, the definition of "Urban art": the latter can also be referred to a branch of "Public Art" because it is realized and designed with public commissions and funds.
Both these typologies of works of art-which include murals, too-arise from the need of many artists trained on the street or even via traditional academic programs to speak again and express their artistic messages through the renewed use of the wall, experimenting with multiple techniques [3]. Surely the favorite support, but not the only one, is the wall and for this reason-especially in Italy where mural painting has found new vitality since the 1920s/1930s-the development of the so-called "New Muralism" movement finds fertile ground.
The choice of the wall, of outdoor and large-sized art, is itself a choice of public nature where the art is clearly designed for everyone to view it. Therefore, these kinds of contemporary mural paintings are all connected to the so-called "Public Art" thanks to the specific choice of the artists in representing often important, politicized, ethical, and social messages directly in the outdoor street context, where all the people can reach them (Figure 1). However, this connotation is strongly rooted both in the street art murals-quick artistic interventions carried out without legal authorization-and in the often financed urban art murals, which are, for this reason, assignable to the public character nature.
As a terrific example of a street art mural with this kind of characteristics, it is shown, in this paper, Migrant Child, realized, as an unauthorized "stencil installation" by the street artist Banksy during the 58th Venice Biennale opening in May 2019 [4]. The artwork, spotted in the heart of the student area of the Dorsoduro district, portrays a migrant child wearing a lifejacket and holding a neon pink flare. The mural's artistic message, which represents a clear and rough figurative icon painted in order to denounce the global refugee crisis, is surely completed by the presence of the water and by the increase or decrease of the tide. In fact, as can be seen in the photomontage above (Figure 1), the high or low tides are also the principal actors in the artistic message, and that is why this street art mural is also truly representative of the Rigglerian definition of street art. Therefore, it is possible to interpret the meaning of Public Art according to, at least, two facets and with different declinations and shades: from graffiti writing to the so called "New Muralism", a recent new artistic movement where diversified techniques are applied on walls in the field of the street, and, more generally, urban art. The "Artwork/Context/Viewer relationship" [5], which interfaces itself with the law of the street and constantly changes according to the artwork's viewer, becomes fundamental for both of the aspects described above, so much so that street and urban murals' decontextualization is considered a loss of their value or, at least, a devaluation of them.
Public Art, accordingly, presents at least two points of view: the one linked to its public normative nature, as in the case of urban art murals often commissioned and financed by public administrations or institutions, where thinking about the conservation of such artworks becomes almost a moral duty connected to the initial artistic project, and the other, also connected to street art murals and referred to its public connotation, as an art with a social character aimed at everyone.
Nevertheless, speaking of conservation only for urban art murals or artworks carried out on commission seems to point to a reduction of the problem where the question "preserve or not preserve?" is surely outdated to leave space for the urgent one, which is "what to preserve and who can decide it?". Moreover, many of the street art masterpieces were also born and executed under an unauthorized context and were linked to more ephemeral gestures but are still becoming vehicles of very important artistic messages, as described previously in Migrant child of Bansky [6].

History, Legal Framework, and Reflections on Protection and Conservation in the Street and Urban Art Murals: "What to Preserve and Who Can Decide It?"
On the one hand, the idea of protecting and preserving urban and street art murals occurs from two principal issues: the (not yet) official, but social, "recognition of them such as works of art" [7][8][9][10] and beloved icons in the communities; on the other, and consequently, the identification of these works of art as "testimonies which spread the values of civilization" [11] and, thus, connected to the definition of Cultural Heritage, (see the Italian normative art.2 p.1, 2 of the Legislative Decree 42/2004) from the last decades of the XX century to nowadays. Therefore, the social recognition and the close relationship to the normative one establishes the necessity of finding a way to preserve their artistic messages in the ephemeral outdoor context.
The definition of Cultural Heritage in the Italian legal "Code" has a great interpretative potential in the lexical definition itself and it was, certainly, thought to also be used for including new forms of art as testimonies of specific historical periods and of the evolution of the special products of human activity called works of art. The graffiti revolution, first in America and then in the other countries, was the first kick off the so-called street art movement. The latter was surely influenced in its evolution by translating its artistic language, especially on murals, in different perspectives and branches depending on the country itself.
Consequently, the introduction of graffiti writing on the Italian national level immediately fits into the contexts of the alternative and underground art and fashion market thanks to the fortune previously collected in America. So, already in 1979, Claudio Bruni, the enterprising owner of "La Medusa" Gallery [12] in Rome, was fascinated by the explosion of graffiti writing in New York and decided to call two famous American writers, Lee and Fab 5 Freddy, to present their artworks in the Roman gallery 1 .
In 1983, the entrepreneur and patron Elio Fiorucci commissioned to Keith Haring, the undisputed king of graffiti and of New York street art of that time, the decoration of his historic shop in San Babila quarter in Milan. The shop, in addition to being frequented by fashion's and art's young lovers since the 1970s, became itself a work of art and a symbol of the rebellion and the freedom of the latest trend expressive artistic movements (even better if illegal!), which the patron and entrepreneur was well aware of thanks to his American trips and of which he was one of the spokespersons for in his collections [13].
The history of graffiti and street art in Italy would materialize further in 1984, thanks to Francesca Alinovi 2 , with the exhibition, "Art of the Frontier: New York Graffiti", created first at the Municipal Gallery of Modern Art in Bologna and then at Exhibitions' Palace in Rome. In conclusion, as a result of the rampant success of importing American graffiti writing from museums and galleries, street art finally arrived to the Italian streets. From there, it would be filtered and reinterpreted through the national context, in all its forms, thanks to an already fertile ground where art on the walls had always been part of the historical and national Cultural Heritage. Finally, the movement, also passing through 1968 and the youth protest, has arrived nowadays to another (and legal) branch called the "New muralism" movement.
In any case, even in Italy, the phenomenon remains connected and rooted to the jamming culture, hip hop, and crews: those from Bologna, Rome, Milan, and Turin in the first place.
Certainly, the spontaneity of the phenomenon is lacking when it comes to its institutionalization, although, fortunately, the artists have given life, over time, to a parallel irreverent production concurrently to their own street artworks playing with the institutionalization in favor of the spontaneity (and vice versa). Hence, the street art of our era reaches the viewer's eyes by winking through the story of an evolutionary (and involutionary) path where the subversive charge of the murals, over time, is taken into consideration as their materials and their site-specific nature. Gradually, these factors reinforced their necessity to be preserved even though the boundaries of the artwork itself are often lost in the renewal of their ephemeral artistic messages due to the ephemeral outdoor context.
In fact, some murals become a sort of installation as a result of their specific and ephemeral spot of realization (and conservation), even though their artistic message become not so temporary because it became socially recognised as part of the communities' landscape and, consequently, also a testimony which spread the value of civilization, which is one of the main reasons why they need to be preserved. The artist's choice for the spot of the mural's realization does not often take into consideration any sort of possible decay process caused by the environment, but instead, the environment itself becomes an actor, as does the viewer, in the artistic message.
Therefore, the first recognition of these murals as a "special product of human activity" or works of art is to be traced back to the communities established by people. These people happens to be different in many ways, unknown but also connected to this field such artists, conservators-restorers, curators, officials of the Italian Ministry of Culture (MIC), etc., but most of all, citizens.
In conclusion, the common and powerful act of all these citizens in the social recognition of street and urban art murals such as works of art, even before their normative recognition as part of the so-called "Cultural Heritage", is already the real first step for the act of conservation of the latter. Therefore, thanks to these preventive acts of care, public or even private institutions and associations in the field will also be able to indicate fundamental communities' opinions related to these issues to the Parliament or the competent authorities in order to develop a national law on this specific topic, thus answering the question, "what to preserve and who can decide it?" 3 .
Moreover, the question above needs to be legally and properly answered as soon as possible in order to preserve an art which is quickly disappearing with the constant changes of the cities. This art arises, most of the time, and even if illegal, from the reawakening of a social and common civic sense for the development of a real consciousness connected to "Urban Beauty" and to the public space ( Figure 2). Surely, the conservation and restoration actions are strictly linked to the legal act of protection, or at least to the protection of the most significant ones, but they should also be connected to the first act of the social recognition of these street and urban art murals as works of art and/or as "part of the communities' landscape urban context" (which is actually the definition of The Landscape Heritage: see the Italian normative art.2 p.3 of the Legislative Decree 42/2004). This social act is, indeed, already strongly rooted and developed in the citizens' consciousness and needs to also be taken in consideration by the competent authorities [14]. In addition to that, it is very important to consider that every street or urban artwork is protected, from the very first moment of their creation, according to the laws of copyright where the creation's act is seen as a special product of the human activity and it deserves, consequently, legal protection. In fact, copyright recognizes, as with any other creator, the street or urban artists' moral rights, their authorship of the work, and other rights of patrimonial content. Therefore, the artists have to also be included in the process of the creation of a national law, especially if their artworks are socially recognised as works of art and located in a public space, in order to correctly legislate and develop the legal act of protection, the legal acts of conservation and restoration and, at the same time, the protection of the artists' moral copyrights on the artwork as a creative act of intellectual property and a special product of human activity (art. 1, 2 of Law 633/1941) 4 . As is deeply known, there are different types of legal acts of protection which might be applied depending on the street or urban art murals and their outdoor context: one of these acts, suitable for these kind of works of art, is surely the declaration of cultural interest with particular environment's jurisdiction, which legally establishes an inseparable connection between the artwork and its site context (according to art. 10, p.3, letter d) of the legislative decree 42/2004). Nevertheless, it is unthinkable to preserve and protect every single piece of graffiti or every street and urban art mural in the outdoor context because of the constant layering and changing of the cities' landscape. Hence, it is essential to create boundaries, firstly through a social preservation, which involves all the citizens, and then with a national (hopefully international, too) and common law making clear what to preserve: In this way, "the act of conservation and restoration" could be applied, even when the protection's legal act is still missing according to the Code, where the social recognition of the artwork first arises, such as a work of art both on public and private building's walls.
According to the above criteria, it could be possible to evaluate a case-by-case situation through a deep dialogue with MIC officers, conservator-restorers, artists, curators, and citizens in order to define the different and specific protection's legal acts. Consequently, various forms of conservation might be taken into consideration, including the application of some invasive restoration actions (if necessary) such as detachment as the very last form of preservation for the murals. The latter would be taken as the result of a critical reflection in order to avoid bitter preservation mistakes or lacks such as the erasing of important murals ( Figure 3) and of their artists' copyright, too [15].

Conservation Reflections on the Street and Urban Art Murals: The Ephemeral Outdoor Context
As mentioned above, street and urban contemporary murals are both linked to one principal context, which is the ephemeral outdoor scenario. For this reason, the developing of a correct plan for the protection, conservation, and restoration of these kinds of works of art, as well as specific programmes for the ordinary and extraordinary maintenance, needs to consider, more than ever, the inseparable relationship between their materials, their conservation environment, and even their viewer. This last fragile axiom is strictly linked to the "law of the street", where all the decay processes are often unpredictable. The outdoor context is strongly influenced by two leading typologies of risk: the anthropic risk and the natural risk.
These two main factors can lead to chemical and physical degradation, biological degradation and aesthetic degradation, hence, activating some of the best-known types of decay processes in mural paintings such as: efflorescences and subefflorescences, blanching, plaster detachments, biological colonization, photochemical degradations, decohesion, flaking, and many other degradation problems from the support to the pictorial film etc. Furthermore, referring to decay mechanisms related to human actions, it is often possible to detect on these murals vandalism writing (due to the lack of recognition of them as a work of art or as a part of the urban landscape) or the simple layering of other urban and street painting films on the wall (i.e., tags, graffiti writing, etc.) also related to the overproduction of this art where often murals became a substitution of advertising boards.
Thus, it has been observed that signs of ageing on outdoor murals attracts vandalism and, sometimes, the appearance of tags (Figures 4 and 5) could be the sign of a sort of "war for the cities' walls" between vandals, writers that sometimes protest against the phenomenon of gentrification, or it could be linked to the urban renewal [16] or directly executed against street and/or urban artists or curators ( Figure 6). Surely, one tag or vandalizing action will attract others, leading, in some cases, to a total overpainting of the mural. Consequently, in these cases, the municipality itself can decide (or be constricted) to re-paint and cover the entire wall, in diverse ways and with different materials, in order to maintain the "urban decor". As described above, murals placed in the outdoor context present a lot of conservation problems connected to the alteration and degradation of the original materials due to the natural risk, which takes in consideration environment agents such as the exposure to the sun, rains, winds, marine aerosols (where present), and strong thermohygrometric changes in the environment. Moreover, the outdoor context is also unpredictable due to anthropic interferences risk such as air pollution or other degradation factors mentioned before and connected to the anthropic activities. All this information need to be collected in order to provide a correct understanding of the thermodynamic equilibrium reached by the mural in the outdoor context with some fundamental conservation actions.

Main Preventive Conservation Actions for Murals in the Street and Urban Outdoor Context
More and more, the operations thought of for these kinds of contemporary mural paintings are connected to the concept of preventive conservation or some actions with the aim of reducing their future alteration and deterioration linked to the ephemeral outdoor context. The research developed until now, but still in progress, is connected to the area of documentation with different programs and aims at the creation of research protocols for cataloging and mapping street and urban artworks, especially mural paintings (i.e., the ones that are running in the Capitoline Superintendency, in the project YO-COCU-M.U.R.O, or in the ICR) [17][18][19].
Nevertheless, it should be taken in consideration the planning of a specific condition report to create a common conservative language especially dedicated to contemporary murals in the street and urban art field with the main technical conservative information collected. It should also be periodically updated according to the quick changes of the outdoor context and the cities' walls. The drafting of these conservation documents by conservators-restorers, even better if standardized by the national competent technical research organisms of MIC, is at the very base for the creation of a database system for the documentation and the archiving of all the conservative information acquired. In addition, the conservative operations in this field, specifically referring to street and urban art murals, are divided in two fundamental branches and studies. The first one will be focused on the in situ conservation of the murals, which requires research protocols in applying specific protection and conservation and restoration materials and methods strictly connected to the outdoor context and its constant changes [20]. The other one, instead, will be connected to the musealization of urban and/or street art murals. In fact, at least in the last 10 years, many important pieces have been detached and moved to galleries and museums and placed in controlled environments (indoor context) for "more or less" conservative reasons, also provoking controversies and debates still in progress in the communities, among the artists, and in all the professionals figures linked to the field principally because of the "decontextualisation and exploitation of the true nature of the street art culture". There are still many open questions of normative, ethical, and philosophical nature in applying detachment as a technical conservation solution, but it is unthinkable to follow just the "conservation in situ line", or even the musealization one, of every urban or street art wall painting, and that is why it is so important to document such an ephemeral art ruled by the street law and its ephemeral outdoor context. Nevertheless, the musealization branch needs to be taken into consideration when it comes to a real conservative necessity, even though it has been strongly criticized because of some conservation abuses carried on and perpetrated in the name of the conservation's field just to fill into the art's system, or worse, to feed the black market, where these specific and particular artworks are always fashionable [21][22][23][24].

ICR Research in Contemporary Murals in the Street and Urban Art Field: Critical Reflections between Preventive Conservation and Restoration
As is well-known, the ICR began research and studies on vandalism and graffiti writing on historical buildings and their outdoor context in late 1997 and developed deep studies on protective and synthetic paint materials in modern and contemporary murals throughout the years [25].
Public art and its conservation and valorisation in situ, especially mural paintings in the outdoor context, has been one of the main topics of interest in preventive conservation, experimentations, and restoration in the ICR for many years, and street and urban art murals were deeply studied, too, both in the laboratories of mural paintings and contemporary art also through the realization of the ICR MA thesis in the field 5 [17,26,27].
Currently, the wall paintings laboratory is running an elaboration of a preventive conservation project based on the building of a common conservative glossary to outline particular forms of damage in street and urban art murals often based on "plastic on a wall" [28], which means the use of synthetic materials on walls, connected to the ephemeral outdoor context and its two main environmental and anthropic risks. Another important part of this research is based on the survey of material and technical issues by interviewing the artists and with the aids of scientific analysis [29]. The project is drawing up with the drafting of an institutional and specific "structure and condition report" to create a common conservative language for contemporary murals in the street and urban art field with the main technical conservative information. Moreover, thanks to the ICR's previous experiences in the cleaning and the removal of synthetic overpainted industrial layers, pilot cases were performed; it also has been possible to develop trials and tests with innovative materials (i.e., gels and supports) for establishing a cleaning protocol for the removal of overpainting layers with similar solubility for urban and street art murals as well, often based on synthetic materials on walls [30]. The project, which involves other research institutions and associations, was built in order to study the application of innovative and green protective materials with the final aim to establish suitable preventive conservation's interventions and to define institutional conservation guidelines for the protection of contemporary urban and street mural paintings in a perspective of a "share for care" conservative program.

Conflicts of Interest:
The author declare no conflict of interest.

Notes
1 Claudio Alberico Bruni Sakraischik  founded in 1953 the legendary gallery "La Medusa " in Rome and, in addition of being the curator of Giorgio De Chirico's general catalogue created in 8 volumes from 1971 to 1987, he was a great promoter and supporter in the importation of Graffiti Writing in Italy. 2 In 2003, twenty years after its opening, the concept store in San Babila Square, lowers the shutter while Haring's paintings are sold at auction. 3 Francesca Alinovi (1948-1983 was an italian art critic who tragically died at the age of 35. She was very attentive to the contemporary art scene and she soon became a sort of "talent scout" of italian and american artists becoming very passionate about Graffiti Writing organizing, first at the GAM Modern Art Gallery in Bologna and then at The Palace of Exhibitions in Rome, the exhibition "Art of the Frontier: New York Graffiti". 4 A brilliant example of this social recognition could be also found in MAAM-Metropoliz: A squatted former industrial complex at Tor Sapienza neighbourhood, in the eastern outskirts of Rome. This huge abandoned site was occupied in 2009 and it now shelters families from many different countries (for a total amount of 200 people). The abandoned complex was literally transformed into a work of art itself, a sort of an anti-museum, as people are living inside it, where street artists have donated their works (especially murals) to support the families and the project. 5 See Art.12 of the Italian law 352/97 and subsequent amendments and additions, art.4 law 237/99, where it is mentioned that the ICR, as technical research organism of MIBACT (now MIC), have to receive all the information's regarding aerosol spray paints and its chemical contents (synthetic resins and solvents) and how to remove them from after application. Alterna-tively, the spray paint factory needs to report all these informations on the labels.