Continuing the investigation of the pesky agents of deterioration, I am blogging about light, perhaps the worst offender. Last blog, our agent was insects, but they are small potatoes next to damaging ultraviolet rays.
Sunlight, as lovely as it can be on a spring morning or glistening on a lake, is positively murder on textiles, paper, wood and leather. The number one greatest threat to objects made of those materials is light. Ultraviolet radiation from natural daylight and fluorescent light bulbs causes damage most quickly, but all light damages over a period of time. Common items that are vulnerable are books, rugs, clothing, upholstery, taxidermy, wooden furniture, works of art on paper and even the drapes that you might use to block the light in the first place.
Less common, but nonetheless nasty, is the damage direct sunlight can do to oil paintings. Some pigments simply fade away, the finishing varnish can turn yellow and the painting surface can heat up, which causes a whole bunch of other problems. Light can even cause wood cell structure to break down in furniture! Light fades, it weakens and it heats. All bad for old organic matter – and the damage is irreversible, even in the hands of a conservator.
Villa Finale has a lovely group of sun damaged objects in the tower room of the museum. It is a small room, meant to provide ventilation for the house, however, when the windows are closed heat build-up becomes very intense, and because it is high above the tree canopy, there is a lot of light infiltration. There was no real reason for Mr. Mathis to venture up in this little room, and due to the sneaky nature of light damage, he most likely would not have noticed the terrible damage it was wreaking.
Here are some pictures of some things in the tower:
These chairs are a pair – one has been shone upon and one hasn’t.
No, this is not just the light shining on the bed, it is the bed shining because it’s been bleached.
As the old saying goes…”Prevention is the key”.
If you have fluorescent fixtures, ultraviolet filtering sleeves can be placed on the bulbs. Lamps and overhead light fixtures can be turned off when not in use, which is not only environmentally friendly, but also a very good collections management practice. For natural light, shutters, drapes and shades can be used to block light, but filtering films that are adhered to window panes are preferable, as they block about 99% of entering ultraviolet rays. And as much as people think you can detect them, they are quite invisible. Shades and shutters are better than nothing, but pinpoints of light can still enter, and are perhaps worse because they are concentrated on one spot.
For extra precaution, you can use ultraviolet filtering Plexiglas on drawings, watercolors or framed textiles. You can also rotate art, furniture and rugs, and anything else that might need a rest from light. You can also live in the dark and only go out at night – at that point, however, your problem may be more than a conservation issue.