What causes paint to change colour over time?

[Superposed_Cat]

What compounds,reactions and factors cause modern day paint to change hue intensity over time? Any help appreciated.

 

[Borek]

I guess it depends on the paint, so you won't get a "one size fits all" answer.

 

[Superposed_Cat]

Pick any you know the most about,

 

[phinds]

Oxidization due to exposure to the air and fading due to exposure to UV (sunlight, even indirect) are the two primary causes.

 

[Superposed_Cat]

Thanks

 

[DrDu]

Google for "lightfastness".

 

[Drakkith]

Google for "lightfastness".

You sure that's not a description of the speed of light?

 

[epenguin]

I guess it depends on the paint, so you won't get a "one size fits all" answer.

Oxidization due to exposure to the air and fading due to exposure to UV (sunlight, even indirect) are the two primary causes.

And broadly pigments of plant origin will be more photosensitive and oxidisable than 'mineral'' pigments so typical Japanese woodcut print of the 19th century the colours will be faded, whilst in a Persian miniature in a book of the 15th century they will be almost like new.