Will sunlight fade acrylic paintings?

[wren]

I assume a painting in lots of direct summer afternoon sun will fade a painting to some extent, but how much danger is there with paintings that get a few hours of morning winter sun from a window that's across the room? My mother-in-law has some paintings I did for her that she really loves--and she's worrying because the late morning sun has been hitting them. Is this cause for concern? It's something I've never really given any thought to...

Is there someplace where I can get a definite anwer on this? - wren

[Laura Morena]

Although I have not had personal experience with having any fade, just look what they go through at museums to preserve works of art. They keep the art at a constant temperature and humidity, with special light bulbs to prevent fading. I would imagine the sun coming through the window each day is changing the temperature of the artwork and is causing a slight bit of expansion and contraction as well as fading. If she wants the painting to last, she should move it to a wall that does not get direct sunlight or look into installing special film on the window to block the UV rays and heat on that particular window, if such a thing exists.

[wren]

Originally posted by Laura Morena
I would imagine the sun coming through the window each day is changing the temperature of the artwork and is causing a slight bit of expansion and contraction as well as fading. If she wants the painting to last, she should move it to a wall that does not get direct sunlight or look into installing special film on the window to block the UV rays and heat on that particular window, if such a thing exists.

Hm... Well, the paintings are clear across the room from the window, and it's in WA state where the winter sun wouldn't change the heat variation as much as the furnace does. So it would be the UV rays she'd have to think about. Thanks for the input. Kinda' frustrating to think about them going into a dark spot--the days can get so dark up there--but maybe I'll suggest picture lights! wren

[rshakesp]

It all depends on the paints you used to make those paintings - if you used student grade paints - get in a car and move them yourself NOW! If you used artists grade then you stand a far better chance, most manufacturers give a good indication of the Lightfastness of their paints on their labels or failing that on their web sites - so check out what they say.

[snuffy]

wren-
Most of the uv light is blocked by the window glass itself - that's why you can't get a sun tan inside the house. Chances are it won't be a problem. If there is no change in the wall paint behind the picture, there shouldn't be a change in the paintings. If you see a "light" area in the wall paint behind the pictures, then consider moving them.

snuffy

[Andrew]

And on the pigment concentration and the actual intensity of light and the wavelengths to which the pigment is exposed. Some pigments are by nature more light sensitive, or fugitive, than others. The more dilute the pigment is relative to the body of the paint (not talking about application) has a minor effect. More important is the intensity of the light source. Most fading is attributed to the UV range, but some pigments fade more in the IR range (which is why some dyed papers fade in a warm room irregardless of light intensity). Generally, a painting should be stand in good stead under normal ambient conditions.

Andrew

[wren]

Thanks very much, everyone! I think it's not a problem. I use high quality Golden or Liquitex paints, and I just checked labels--the ones I used are considered to have excellent lightfastness. I might be more concerned if this were a wall close to a window that had summer afternoon sun beating through it, but the more I think about it, I just can't imagine it being harmed by morning winter sun coming through a window clear across the room.

Come to think of it, I've never seen anything at all in her living room faded, and she never closes those patio drapes. She just got me to questioning myself because she loves that painting so much and was so worried--it's a portrait of her husband who died many years ago. Thanks again! wren