This is a line of text I found on a website.
"Research has shown (above) that 40% of fading is caused by UV rays. Another 25% of fading is due to heat, with 25% being caused by normal visible light. The remaining 10% cause of fading is from indoor artificial lighting, humidity, and poor dye anchorage. Visible light and UV radiation cause fading and a lack of moisture, especially in the cloth materials used to cover books."
Is what's said true? I always thought that only sunlight or UV would cause fading. Or does it only apply to certain materials?