Webinar: How Does Light Exposure Affect your Art Collection?

This webinar looks at how light exposure can affect an art collection in terms of its condition and its value. Condition affects market value and light is the single factor that triggers deterioration in art. This webinar will explore the problem and suggest solutions to increasing the longevity and market value of your art collections.

Webinar Transcript

And good morning, good afternoon and good evening,  wherever you are. Welcome to this first ArtRatio webinar on the subject of ‘How Light Exposure Affects your Art Collection’. I am your host: my name is Manoj Phatak. I’m a Chartered Engineer with a background in physics and Founder & CEO of ArtRatio. We are display case manufacturers using smart glass to protect fragile and rare art collections. A quick shout-out to all the people who are connecting to this webinar from different parts of the world. I see messages coming in from Canada, from the UK and also from other places such as Hong Kong so welcome, everybody.!

Our partners include the Museums Association where we are Corporate Members; LAPADA, where we are Approved Service Providers; the Institute of Conservation otherwise known as ICON in the UK; and SEAHA, who provide doctoral training in the area of arts and heritage. They are backed by UCL London, Oxford and Brighton Universities.

So, who is this webinar for? It’s primarily for collectors, whether you are private, corporate or institutional; it’s also aimed at the art trade which includes auction houses, dealers and galleries. It’s also aimed at architects and interior designers and for ancillary services such as insurers, consultants and art advisories. 

So let’s get straight into it and look at the first question which is ”Where is Art typically exhibited?’. We are all used to going to museums and galleries of course but we often forget that there are collections which are exhibited in private residences, for example in corporate offices. This is where the private collector and the corporate collector comes in; as well as in art fairs and in auction houses, whether they’re having a public auction or it could be a private sale. We can also find art exhibited in hotel lobbies and in corporate events for the banking sector for example, which is very popular as well; as well as a recent trend to display art in airports and even in super yachts. So what do all of these places have in common? And that is abundant daylighting. Now, with the exception of museums which tend to be very controlled environments, all of the other examples that I give here have abundant daylighting, as well as climate controls which are optimized for humans and not art necessarily. There are also other risks such as vibration, pollution, accidents and theft of course.

Why display art? Well apart from wanting to enjoy the beauty of art for learning or enjoyment, there also comes the issue of exposure and value. Dr. Sarah Thornton, who is the author of the book ‘Seven Days in the Art World’ claims that collections are more likely to increase in value if they are seen by the general public, because art accrues value through exposure; and she claims that this is particularly important for contemporary art.

The other quote which I wanted to share with you comes from Orlando Rock, Chairman of Christie’s, who says that the condition of a piece can be crucial in determining its value. So we have two pieces of information here; a connection between value and exposure (or exhibition); and the connection between value and condition. 

So what we’ve done is to put this into a graph and on the horizontal axis you can see exhibition, in other words how much exposure the object is getting and we control that of course. On the y-axis we can see value that could be interpreted as the market value. In other words economic value; or it could be cultural value; or it could be sentimental value and if Dr. Sarah Thornton is right (and all her peers agree with her), then in the initial part of the graph as exhibition increases, we should see an increase in value. In the third part of the graph as exhibition continues unrestricted, we can fall back on the simple rules of physics and chemistry, which is; the greater the exhibition, the greater the light exposure; the more damage will be done to the object; the condition will fall and quite possibly then as a result of that, if it’s Orlando Rock is correct, then the value will also fall. So, if the first part of the graph is going up; and the third part of the graph is coming down; there must be a peak somewhere. We think there must be a maximum value for which you can exhibit. i.e. an optimal amount of exhibition time which maximises the value of your art collection. Now we at ArtRatio call this the ‘balance point’ between exhibition and conservation. We don’t know really what the graph actually looks like; but we are surmising that there must be a peak somewhere; a balance point; an optimal point.

Which types of materials are most sensitive to light? Well, we can turn to the British Standards Institute document BSI PAS 198 and that talks about four types of materials; silk, nylon, works on paper and color photographs, which are all highly sensitive to light. To answer one of the questions which I posted on LinkedIn; which of these types of materials is not sensitive to light? Well, you can have works on paper based on wood pulp and those based on rag paper; and curiously enough those based on rag paper (or cotton paper) are NOT sensitive to light; that is according to the British Standards Institute document BSI PAS 198, which is quoted below. But so far we’ve only talked about the substrate material. What about the dyes and the pigments? Dyes used for tinting paper in the 20th century are all very sensitive to light, as are insect-based extracts such as carmine; they’re all very sensitive to light, as are most early synthetic colors, for example anilines.

How serious is this issue? Well if you look at the typical light levels that you would expect to find in a museum, which might be from 50 lux up to 200 lux, depending on where you are in the galleries, if we take an average value of 100 lux and you were to exhibit some of the most sensitive materials we just looked at; silk, nylon, wood pulp based paper; then you would expect to see a *noticeable fade* in anything from seven months upwards and an almost *total fade* in anything from 15 years upwards. We are not too worried about the museums because they know what they’re doing and they’re very controlled environments. What we’re most concerned with are the private collections, corporate collections and retail collections, which tend to get exposed to excessive amounts of light. So if you look at a typical private residence or an office then you can expect to find something like 500 Lux; five times the amount what you’d find in a museum. And if you were to exhibit any of the fragile materials we just looked at in the previous slide, you can expect to see a *noticeable fade* in anything from seven weeks upwards; and almost *total fade* in anything from five years upwards. If you are a collector / investor, I’m sure that you are not wanting to see a deterioration in the condition of your investment (and therefore the value of your investment) within five years. If we look at the retail environment, so now we’re talking about dealers and galleries as well as luxury retailers, those exhibiting silk, textiles and leather for example, you can expect to find something like 800, 900, or 1000 Lux in those types of environments. And if you exhibit fragile materials in 1000 Lux, you can expect to see *noticeable fade* in anything from 7 days and you can expect to see almost *total fade* in anything from 6 months. So from The Art Basel Report 2019 we know about 75% of stock in dealers and galleries takes more than six months to sell, which means that fragile materials are actually decaying whilst they are on display for sale purposes. So clearly the business case is very clear here – the biggest need really comes from private, corporate and retail collections.

What is light? Well here you see an image of the sun and the different levels or wave bands, such as ultraviolet on the left hand side, visible in the middle and infrared on the right. To the left of this diagram (which is not shown), are the gamma rays and the X rays but they are all cut out of course by the Earth’s upper atmosphere. The same goes for UVC and parts of UVB which are also cut out by the Earth’s upper atmosphere. Ultraviolet-A (UVA) however is not and it gets straight through to earth and it can go straight through float glass so we do need to worry about UVA. We intend to have a webinar on the subject of ultraviolet light. If you’re interested in seeing such a webinar please put a message in the chat. Up on the right hand side, you see infrared. We’re going to talk a little bit more about infrared right now.

So there is a domino effect. With the sunlight that’s coming down to earth, about 50% of that is infrared. The highest frequency part of that it’s called near-infrared and it’s not blocked by float glass. That’s typically the type of glass that you would have in your window and it causes heating. If you put your hand out in the sun, what you’re feeling on your hand, that sensation of warmth, that is near-infrared. It causes a rise in temperature and for every 5 degrees C rise that it might produce on your artworks you can expect to see a doubling in reaction rates of organic materials. That results in desiccation (drying out). Now because there is an inverse relationship between temperature and humidity; as the temperature goes up, the humidity (or relative humidity) comes down. So for every 2 degrees C rise, you can expect a reduction of about 6% in the relative humidity on the item’s surface, leading to the movement of moisture; and that can result in flaking and delamination. Now most people stop there. They talk about light, temperature and humidity. We go a couple of steps further. So imagine for a second that the relative humidity has dropped; you can imagine that there’s less moisture in the air and we know that water is electrically conductive; which means that there is less water in the air which means that the air has reduced electrical conductivity. i.e. Reduced relative humidity reduces the electrical conductivity of air. And so if you have any insulative surfaces, like glass or acrylic; simply by rubbing a textile across it, you can transfer electrostatic charge to that insulative surface. Normally that charge would dissipate away thanks to the moisture in the air, but if you reduce the relative humidity that charge cannot dissipate away to electrical earth. What happens to it? It accumulates and it accumulates, up to the point where in the extreme case you could get a spark; it’s very unlikely thankfully enough; but what’s more likely to happen is that you will get a buildup of the electric field. And that can attract away friable media such as graphite and chalk and pastels. So basically your work of art is going to be deteriorated directly by the electric field. If there is a very close distance between the glass and the artwork that’s one thing you need to work on; that’s why we have anti-static coatings. You might think that’s not very common. In fact we took part in a project a few years ago where that actually turned up as an issue identified by the museum conservation staff. I’ll talk about that project in just a minute. Just to finish off this slide; reduced relative humidity also facilitates the transfer of dust by electrostatic forces within the display case or within the room and that reduces the air quality also. So there’s a fascinating domino effect and it all starts with sunlight; and it moves on to impacting the temperature, the humidity, the static electricity and the air pollution. And all of that is documented in BSI PAS 198.

So what solutions are available? Well in the extreme case you can just go for permanent storage, climate-controlled; perhaps you could go for curtains on the windows or blinds or shutters; they could be manual or motorized. In the example you see on the left hand side it’s a manual shutter, which is placed directly on the display case. Of course it relies on user compliance to actually make sure that the people who lift up the shutter then actually pull it back down again; otherwise the work suffers from light damage. Some museums have object-rotation schemes in place and also passive filters. These types of coatings or films can be placed onto light fittings or onto the window facade itself. They don’t change their behavior; whereas active filters do change their behavior and these are normally films which can be adhesively placed on the window surface or often they’re laminated inside the glass. They can be placed on display cases for example or on the window facade. So some examples of active filters include electrochromic glass, SPD glass (that’s the type of glass we use in our display cases), PDLC glass, APD glass, photochromic glass; thermochromic glass etc. There are quite a few technologies out there. If you are interested in knowing more, we are planning to do another webinar just on active filters for art collections. If you’d like us to do that please give it an upvote and tell us in the chat on the right hand side.

How does ArtRatio solve the problem of light exposure? Well if you look at an existing vitrine you find in any museum or any collection, you have 100 Lux shining down through normal glass which you might have 95 percent transmittance, so 95 Lux will get through. If you multiply that by the 3000 hours that the exhibition is open per year then you get 95 x 3000 = 285,000 Lux.hours of exposure in a year. If you’re talking about exhibiting some of the fragile materials that we looked at before, then they will typically have a maximum exposure limit of 15,000 Lux.hours in a year; which means that the example on the left is exceeding the light exposure by almost 20 times. Our solution which appears on the right-hand side (that’s the ArtRatio vitrine) has the same amount of Lux coming down 100 Lux, but this time we’re using electro-optic glass or the active filter glass I mentioned before, which has a variable transmittance from 0 up to about 50%. Which means that either 0 Lux gets through, in other words it is opaque, or a maximum of 50 Lux would get through in this particular example. So in other words, half of what’s coming from the light source. If you multiply 50 Lux by 300 hours per year which is the time that we’re viewing the objects, that corresponds to a 10 percent popularity, so instead of 3,000 hours how many people are actually seeing the object let’s say about 10 percent of that time, so 300 hours multiplied by 50 Lux; that would give you 15,000 Lux.hours per year, which is within their recommended maximum exposure limits for those types of materials. So ArtRatio vitrines allow you to tune the amount of exposure according to the light sensitivity of the objects inside the vitrine. 

Here’s the project which I mentioned before; this is a project we did at the Royal Engineers Museum in the UK. The object that you can see in the frame on the left hand side is the *original* map of the 1815 Battle of Waterloo. And when the museum contacted us, they specified two main requirements; one of course was that this object is very light-sensitive; and secondly this document still has the original graphite pencil markings of the 1st Duke of Wellington. That map was used in the actual battle! And apparently it still has the blood of one of the soldiers who was killed in the battle. So it’s a fascinating document historically of course; very important and we have a blog article which is highlighted just below in the URL, which explains a bit more about what we did to try and reduce the lift-off of the graphite pencil markings as well as reducing the light exposure damage on this important object.

So we are boutique manufacturers of smart glass display cases, frames, tables and smart plinths. We’ve had the great pleasure over the past 10 years to protect some very important, even iconic, objects. There are some examples given here; 15th century Books of Hours at the Swedish National Museum; original books by Sir Isaac Newton himself for a private collector in London; the Battle of Waterloo map of course as I mentioned earlier; but also another post-battle Waterloo map for a private collector in London; and then an original Torres guitar from 1888 at the Spanish Guitar Museum. So we have finished the webinar. I would like to ask you if you have any questions please fire away. 

A question coming from Pandora and she asks: Can you switch off the smart glass remotely? Yes that is possible, it’s connected to the Internet or rather to your own intranet, and so we can find ways to switch it off from a number of different locations. Of course we try to do this securely so that other people can’t do the same. Okay, so thank you very much for your time and I wish you a very good day and I hope to see you on another ArtRatio webinar in the near future, thank you very much!