A wood lamp emits ultraviolet (UV) light and is a diagnostic tool used in dermatology to determine whether a person has a fungal or bacterial pathology on the sking or scalp. If so, the area illuminated by the wood lamp will fluoresce, becoming apparent in different colours associated with different pathologies. Perhaps you have ever undergone this test. The doctor will have told you to close your eyes to protect your vision and the light in the room where you are he will have turned off to highlight the fluorescence. Among other possibilities, if it turned out light blue means that you have normal and healthy sking; yellow is oily skin with acne; brown is for pigmentation and blackheads; and if white spots appear, drink more water, because you have dehydrated skin.
But surely you had not stopped to think that his technique is also applicable to diagnose similar pathologies in movable cultural heritage assets made of organic materials, for example wood or resin sculptures, or paintings covered with varnishes madre from three resins. The passing of the years, inadequate conservation conditions and dirt are defining aspects in the appearance of fungi or the yellowing of varnishes, so that if sculptures or paintings are illuminated with a wood lamp, we can clearly distinguish fungal conditions, and the extent of dirt (even where they are not yet perceptible to the naked eye), or if a painting has been touched up because the yellowing of old varnishes turns fluorescent.
Heart of Jesus inspected with wood lamp
In the ITEHISproject a wood lamp that emitting light around 365nm (UV) and producing fluorescence around 500nm (perceptible by the human eye) has been used to inspect a statue of the Heart of Jesus from the late 19th century, validating the fungal infection (especially mold) and making evident its true extent.
A wood lamp thus becomes an absolutely effective, eay-to-use, non-invasive and economically admissible mean, even for a person like you and me, to help clean and restore our heritage. A true example of a “low-cost” technique to keep it there. But this does not end here, because further R&D is required to associate new colours with new pathologies in a moment where climate change and human globalization bring “bugs” that do not correspond to the latitudes where they currently appear. But don´t worry about that, CARTIF is already taking care of it.
Cultural heritage, in the broad sense, is the legacy received from our ancestors, which becomes the testimony of their worldview, their ways of life and their way of being, having to be passed down to future generations. Knowing the cultural heritage is to know the identity of a specific society and let me dare say that, without doubt, it even helps us to discover ourselves.
When we are traveling to a certain place to “pick up” that knowledge, but being far away from stereotypes and trivializations, we are doing cultural tourism. Despite the fact that this type of tourism is sometimes controversial (fundamentally due to how resources are managed), it is unquestionable that it has nothing to do with sun and beach tourism. Even though Spain is the second country in the world for highest quantity (and quality) of cultural (and even natural) heritage, it surprisingly continues to present and sell ‘sun and beach’ tourism as almost exclusive. Cultural tourism represents a great opportunity for local development, decisively contributing to conserving and making heritage sustainable, since it has already been proven that generates resources and employment for the community. But for this to happen, it must be oriented not only for the benefit of cultural heritage in itself, but also for the people who inhabit the place where it is located. Only if the inhabitants are really an active component in tourism development, can the spark arise between heritage and cultural tourism, and then it will end up being a well-matched marriage beyond convenience.
The fact is that since the 1970s, when UNESCO launched the Convention on World Cultural and Natural Heritage, together with proposals to conserve and promote it, cultural tourism has experienced huge growth throughout the world, but especially in Europe, where it became really important since the 1980s. In fact, currently there are 1121 declared World Heritage Sites; the majority of them spread around three countries, two of which are European: China (55), Italy (55), and Spain (48).
Europe is a key cultural tourism destination thanks to an incomparable cultural heritage that includes museums, theatres, archaeological sites, historical cities, industrial sites as well as music and gastronomy. According to CARTIF’s analysis in 2021 for theTExTOUR project, it is estimated that cultural tourism accounts for 40%of all European tourism. This is generating 5 million direct jobs and contributing 143 billion Euros per year to the EU economy. Indeed the EU promotes a balanced approach between the needs to boost growth on one side, and the preservation of artefacts, historical sites, and local traditions on the other.
Pandemics apart, it is estimated that cultural tourism will remain one of the key markets in Europe. Interestingly, cultural tourists spend 38% more per day and stay 22% longer than other tourists. Germany is the largest European source market in terms of market size, followed by the United Kingdom, Italy, France, the Netherlands and Spain. Trends show cultural tourism is slowly changing into creative tourism. With it, tourists actively participate in cultural learning experiences, getting in touch with local people and culture.
Cultural tourism originally was primarily driven by the interest of the baby boom generation (born late 1950s – mid 1970s) to visit major cultural sites and attractions, such as museums and monuments, often travelling in groups. The generations after them: generation Y (millennials: born 1980–1995) and generation Z (centennials: born 1995 – 2010), drive the demand for more authentic, unique, small-scale and personal experiences, plus the demand for popular and everyday culture. For them it is more important ‘to be’ somewhere, rather than ‘to go’ somewhere. These generations prefer to travel on their own, thus flat rental platforms and personally-driven services at local level are growing and growing.
Of course technology has made a substantial change in the habits of travellers. The recent publication of five new standards by the Spanish Standardization Committee (UNE) contributes to providing solutions to the challenges that destinations as well as the companies and agents that operate in them must address through a digital and sustainable model that definitely fits like a glove to the cultural tourism. This model strongly needs to be equal in technological and social development to the digitization of cultural heritage, which is the great pending issue, but CARTIF is ready to help. Do you need us?
The word “Digitization” is ubiquitous today. The term is extremely used but its meaning is worn out when taken to a specific terrain. Answering to how?, with what?, for what?, and even, why? for the particular case of Cultural Heritage it is not an easy taks, nor closed. Digitization and Heritage is a Romeo and Juliet style romance (to make a cultural simile), where the respective families view the matter with suspicion, even when it is destined to be a well-matched marriage, not one of convenience.
Digitization sounds technological, state-of-the-art. Heritage sounds archaic, old-fashioned. Putting one together with the other, and avoiding formal definitions (otherwise non-existent), it is proposed to define digitization in this case as the incorporation of digital technologies (those based on electronics, optics, computing and telecommunications) to the products, processes and services that organizations follow and offer for research, protection, conservation, restoration and dissemination of Cultural Heritage.
Digitization affects the way of facing work, the proper way of working and the organization in itself, modifying its structure and managing. This alteration in the organization schema causes an atavistic fear of losing the artisan and professional-knowledge supported value that features the companies in the Cultural Heritage sector, made up of more than 90% by SMEs in the EU. This is the real reason why they take the longest to “digitize”. It is not just an issue about buying, installing and operating computers, software and wireless networks. The change is deeper: it is not a question of appearance; it is a fundamental question. But it is well worth remembering that the workshops and people who appear in history and arts books today because the works they have bequeathed, are indeed famous for having innovated and used the best technologies available on their time.
But, what are the technologies at stake today for the Digitization of Cultural Heritage? Without being exhaustive, and also being aware of leaving things in the pipeline, the most demanded technologies are summarized below:
Multidimensional modelling and simulation (including Heritage BIM -HBIM[1]-): exact 3D virtual replicas of movable and immovable assets; mechanical, electrical, acoustic, lighting and signal coverage simulations with specialized software; 4D (evolution in time). The HBIM parametric modelling is remarkable to complying with Directive 2014/24/ EU and also to addressing extra dimensions: 5D (costs); 6D (sustainability and energy efficiency); 7D (maintenance).
Sensors, Internet of Things (IoT) and 5G: multipurpose devices for capturing, combining and communicating all kinds of data over the Internet. The 5G allows making between 10 and 20 times faster the traffic of these data compared to current 4G mobile communications. These technologies are typically used in structural and environmental monitoring for condition assessment.
Data analytics to get useful information: cloud computing (to archive all kind of information and making it accessible and searchable from anywhere and from any device connected to the Internet); edge computing (local computing -on the axis-, to improve response times and save bandwidth); big data (massive treatment of structured and unstructured data – in the order of Petabytes: 1015 bytes-). The determination of causes and effects, together with the prediction and characterization of behaviours (including visitor flows) are common examples
Artificial intelligence (AI): machine learning (ability to learn without specific coding) and deep learning (learning based on neural networks that mimic the basic functioning of the human brain) are well-known. One example is the Gigapixel technology to enlarge images to see tiny details thanks to intelligent computer processing of extremely high-quality photographs. Another example is the automatic recognition of symbols or animal species in a prehistoric rock engraving on which a-priori nothing can be distinguished.
Systems dynamics and informational entropy: they are ways of studying adaptive mechanisms in complex and changing systems (such as all those that humans forge -which are precisely characterized by creativity and culture-) to make predictive models or to support decision-making and management.
Computer vision: capturing and processing of images by cameras that operate in one or more spectral ranges to see beyond our eyes also at all scales (from space with COPERNICO satellites, to the microscopic world): search for patterns, detection of pests , humidity, alterations, irregularities and falsifications, definition of authorship and artistic techniques, conservation assessment. Applied to video analytics, it is very effective in guaranteeing the security against theft, vandalism or looting.
Digital twins: combining some (or all) of the previous aspects (multidimensional modelling, simulation, computer vision, sensors, IoT and AI) upon a virtual replica ready to remotely work under a multidisciplinary approach, allows to anticipate possible problems and experiment safely before performing any intervention, helping to its optimal planning. It can be applied to movable assets, but it has special significance in immovable ones.
High-quality audio and video: Hi-Res for audio and FullHD, 2K and 4K for video are words already entered in our lives. They allude to the highest attributes and durability of the audio and video formats that can be used for the registration of intangible heritage or the broad dissemination of heritage in general.
Virtual reality (VR), augmented reality (AR) and mixed reality (XR): to recreate spaces, decorations and configurations, past or future, even to look into planned interventions upon 3D models using special glasses or smartphones.
Ontologies and semantics: to uniquely name and hierarchically structure the constituent elements of movable or immovable assets and cultural landscapes so that they are understandable both by specialists and laymen regardless of their language and cultural background.
Interoperability: to synchronize data, systems and processes nevertheless of their origin and format.
Cybersecurity: to defend against malicious attacks on computers, servers, mobile devices, electronic systems, networks and data. Blockchain allows avoiding falsifications as well as guaranteeing the authorship and the digital visa of projects.
Robotization and 3D printing: configurable robots (adaptable, shippable and remotely-assisted) allow the modular construction of specific elements in-situ. They also allow the automation of inspection, cleaning, assembly, conservation and restoration processes in dangerous or hard-to-reach places, quickly and accurately. It can be combined with 3D printing for sealing, insulating and watermarking in different materials and finishes. Particularly 3D printing allots functional replication (total or partial) at different scales to create prototypes, parts, mock-ups and test series.
Nanotechnology and new advanced materials: the continuously increasing processing power of computers and their combination with the hardware of machinery allows the study and manipulation of matter in incredibly small sizes (typically between 1nm and 100nm), resulting in a wide range of materials and techniques usable in conservation and restoration.
In March 2021, the European Commission published a report that reviews and evaluates the actions and progress achieved in the EU in the implementation of the Recommendation (2011/711/EU) on digitization, online accessibility and digital preservation of cultural heritage as one of the main political instruments in those matters[1]. The ecological and digital transitions are, in fact, the keys to the agreement on the so-called Recovery Plan for Europe[2]. EU Member States have agreed on the need to invest more in improving connectivity and related technologies to strengthen the digital transition and emerge stronger from the COVID-19 pandemic, transforming the economy and creating opportunities and jobs for that Europe into which citizens want to live. During the confinement society has shown that Cultural Heritage in digital format was a true social balm, with museums and collections open online 24 hours a day.
Thus it is the right time and there are no general solutions for “digitization”. Cultural Heritage is not about producing thousands of cars, parts or packaging per day. Quite the contrary: each company, each project, each asset must be considered for what it is: something unique. To make a clear example, imagine somebody getting into the supermarket and asking ‘what is there to eat?’ The answer, consonant with the perplexity, could be: there are from precooked to fresh, meat, fish, eggs, dairy and sweets in all possible varieties. It depends on your culinary tastes, your hunger and the time you have, your nutritional needs, the time of day … In short: particular problems require particular solutions.
The BIM approach (Building Information Modelling) is all around Architecture, Engineering and Construction professionals, but when it comes down, very few companies are founding their daily work on this paradigm and applications are really far from being homogeneous. BIM is many times (let’s say “usually”) incorrectly identified as a specific software package or a type of 3D digital model. However, BIM is much more than a newer version of CAD or a 3D visualisation tool.
The BIM approach provides a digital featuring of a building or infrastructure throughout its whole life-cycle, adding extra information to help making better and more-timely decisions upon a 3D model that allows a multidimensional analysis: 4D (evolution); 5D (costs); 6D (sustainability -including energy efficiency-); 7D (maintenance).
Although there is still a lack of knowledge on how BIM and associated digital innovations are applied across European countries, the European Directive 2014/24/EU imposes BIM Level 2 for government centrally procured projects. Level 2 refers a collaborative process of producing federated discipline specific models, consisting of 3D graphical data (those visually represented) and semantic data (those significant additions) as well as associated documentation (for instance: master plans). Information is exchanged using non-proprietary formats, such as Industry Foundation Classes (IFC).
Consequently the built heritage is subject to BIM for the purposes of documentation, conservation and dissemination, but the distinctiveness and sensitivity to meet heritage demands requires technological and methodological particularizations leading to the concept of Heritage-BIM (H-BIM). The purpose of H-BIM is to provide a 3D parametric model as a “container” of information generated all over time by different procedures, by different people, and from different sources (hw & sw). The model would capture the multidisciplinary nature of Heritage, far away from the simplicity and modularity of conventional construction, and would be very useful to study, evaluate the state of conservation and plan interventions on the assets in a profitable way. It is quite a challenge for a sector where digitization is a pending issue.
This technologically means facing many challenges, starting with the minimum amount of graphical and semantic data that would be adequate to support the activities of the sector. Two of the most important are:
The combination of 3D data with different types of images (thermography, high resolution photographs or multispectral recordings) to produce a really useful H-BIM model for exhaustive assessment.
The photorealistic texturing of 3D models for a rigorous representation of reality.
Both aspects are being worked by CARTIF to decisively help companies, managers and public administrations in the digitization of Cultural Heritage.
In two previous posts [When the Historic Buildings Talk (I) and (II) apart from making clear the importance of the conservation of the built heritage as long as describing the environmental factors that influence such conservation, we have already faced the temperature and the humidity as the two key factors to be monitored. Anyway, and in case you forgot about it, there are other aspects that also must be monitored to avoid deteriorations resulting in expensive and time consuming restorations:
Lighting (natural and artificial).
Pollutants.
In this post we are going to get involved with lighting, which mainly affects the movable goods that decorate or treasure the historic buildings. Be patient, pollutants are left for the next (and last) delivery.
Illumination can be of natural origin (coming from the sun) or artificial (coming from electrical sources), but in any case is an electromagnetic radiation that covers three ranges: infrared (IR), visible (VIS) and ultraviolet (UV). We usually call “light” the visible part to human eyes. UV radiation has a smaller wavelength than VIS and is the one with the highest associated energy. IR radiation has a longer wavelength than VIS radiation and is less energetic. Both UV and IR radiations are not necessary “to see”, but they do influence the deterioration of the materials.
When a work of art is illuminated, whether it is a painting, a polychrome, a tapestry or a parchment, the whole range of radiation (IR, VIS and UV) is absorbed by the materials of which it is composed. This radiation is associated with energy capable of altering and degrading the molecular structure of many materials, especially the most “perishable”, such as those of organic origin (textiles, pigments, leather and paper).
The UV component (highest energy), is the one with the greatest capacity to alter the materials, disintegrating and weakening, producing their yellowing. The VIS component is able to decolorize the most sensitive pigments. On the other hand, the IR component produces a heating effect that accelerates certain chemical reactions.
Thinking about this, it seems that for the assets we keep in museums, churches, hermitages, castles, palaces, archives and libraries, it would be best to preserve them in the dark. However, for study, conservation, and especially for exhibition purposes, some kind of illumination is required. Following the criteria of the IPCE, which establishes the Spanish National Preventive Conservation Plan (PNCP), these are the parameters to evaluate the risks derived from illumination:
Intensity of artificial and natural sources.
Exposure time to the illumination.
Spectrum (range) of emission of the artificial light sources, knowing if they emit in not-visible radiation bands.
Incidence of natural illumination, its orientation, and whether the radiation is direct or diffuse.
What lighting control measures exist on-site.
In turn, the assessment of the damage caused by lighting must take into account the following aspects:
Since this damage is cumulative, we should flee from high levels of illumination, but maintaining a commitment for adequate vision. By giving concrete values: 50 lux for the most sensitive materials and 150-200 lux for medium-sensitivity cultural assets.
Damage is determined by the amount of illumination, i.e. the intensity of illumination during the time an asset is exposed (lux / h). Thus, keep in mind that the damage in the case of high illumination levels with short exposures would be the same as with low levels and longer exposures.
The degradative effect of lighting also depends on other environmental factors such as humidity and air pollution.
Therefore, where we place our cultural assets, how natural light affects them, and with what kind of lamps we focus on, are critical aspects for their proper conservation (see Figure). CARTIF offers advice and tailored solutions based on a proven experience of more than 20 years in applied research to Cultural Heritage.
