Which Artwork Materials Fade Most with UV?

Manoj Phatak, CEO ArtRatio
10 May 2019

Short Answer

The most UV-sensitive artwork materials include silk, nylon, most colour photographs, most dyes used for tinting paper in the 20th century, lake pigments, wood pulp papers and even alcohol-preserved zoological specimens.

Don’t take our word for it. This is according to the British Standards Institute document BSI PAS 198, artistically entitled ‘Specification for managing environmental conditions for cultural collections‘.

(Yes, that is quite a mouthful).

Oh, by the way, this document has now been superseded by standards BS EN 16893:2018 and BS 4971:2017.

Are You Tired of Hearing About UV?

Then we will not tire you any more. Simply to say that, if you care about your art, you will do everything under the sun (pun intended) to stop ultraviolet from reaching your most fragile items.

Wait, You Want To Know More?

Read on…

Raining Cats and Dogs

The diagram above shows that the UV raining down upon us has a shorter wavelength than visible light, i.e. it has higher frequency and thus more damaging energy. UV is invisible to humans (but not to cats and dogs, curiously). And it is normally divided into 3 broad subranges:-

UV-C: This stuff kills you. Thankfully, the Earth’s upper atmosphere stops such radiation from literally frying all life on the planet.

UV-B: This stuff penetrates the earth’s atmosphere and gives us all a nice suntan (and not so nice skin damage, like melanoma). If it reached art, it would surely destroy some objects in a matter of minutes. Thankfully, common float glass stops all UV-B radiation.

UV-A: This is the one to watch out for. Display cases made from float glass will not stop UV-A. This radiation requires filters (either plastic or specially formulated glass) to stop it.

UV damage is cumulative, irreversible and proportional to the exposure, which is the amount of light incident on the object multiplied by the time exposed.

If you were to look at a graph of light levels varying through the year, the exposure would be the area under the graph.

So What Can I Do About It?

There are many solutions available and it would be a mistake to discard them out-of-hand without first knowing the requirements of each item in the collection.

As BSI PAS 198 states, “care of collections requires an understanding of the different categories of object and their different requirements“.

One Size Fits All?

Not really. Based on the popularity, value and condition of the objects, you may choose some, or all, of the following solutions to arrest UV:-

UV Blocking Plastic and Glass on window facades or the display cases themselves
Avoiding the use of Compact Fluorescent Lamps (CFLs), since they emit UV
Motion-activated lighting to restrict the time that the object is exposed
Electrochromic or electro-optic glass or plastic (which changes its transparency based on an electrical signal), again possibly activated by presence or a timer
Object-rotation schemes
Window Blinds, Filters, Curtains, etc

So, It’s Curtains For You?

Not necessarily. Each technique has its cost and benefits. Each technique will be more or less effective.

The choice should be guided by a deep knowledge of the materials on each item. If you want to know more, we have plenty of material in our Blog to inform you.

If that is not enough, or you have a specific item, feel free to contact us and we can discuss the best options to protect your collection.