Why do reflections appear better on black paint than white?

lawrenceSA

lawrenceSA

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Hi all

I would like to be able to explain to a customer WHY it is that a white/silver car will not provide the same type of reflections as say a black one.

Can someone please explain this to me as simply or as complex as is needed to do so, or point me in the direction of some online reading to get to the answer.

Thanks
 
without any further explanation, the fact that black absorbs all spectrums of light, you won't have any washed out images in it, say that you stand in front of a panel that is red and a panel that is black. the black panel won't make you look dark because there is no change in the reflected images colors.

on the other hand, when you look at the red panel you are more likely to see less color definition. the reflection you are seeing is coming from the clear coat, but the background color absorption would be affected by the base coat.

i think it would be safe to say that the color black would have far less light changing properties than another color so you would have far more easily distinguishable images, making it look like a better mirror.


as far as the mirror effect of the paint all comes down to the clear coat itself and how level and glossy it is. the less tiny peaks and valleys you have, the shinier it will appear. when light hits the surface, if it is nice and smooth you will get a nice uniform reflection. but as the surface gets rougher and rougher (not orange peel rough, but sanding or dirty rough), you will lose that light to diffusion through scattering. take a flashlight, if you have tried a couple different kinds of flashlights you know the cone inside the head can either be a very glassy and mirror like surface, or it will be a very rough and almost orange peel like surface. the glassy surface will give a very distinct beam of light due to the nice smooth flat surface giving a good reflection. whereas the rough one will diffuse the light giving a more spread out softer glow due to the light being more scattered.

reflections are basically the way the light hits the car and is reflected back.
 
Thanks for your reply!

Would it be correct to say that there is an element of the white paint (base coat) reflecting light back to the observers eyes that almost washes out the light being reflected back to the observers eyes from the clear coat.

Whereas on a black car, no light is being reflected back to the observers eyes from the base coat (as black absorbs light) and thus the light being reflected back to the observers eyes from the clear coat is more easily seen, as there is better 'contrast'?

:help:
 
Simply there is no contrast with white paint and white light like there is with dark paints. It like writing on a dry erase board with yellow compared to writing on a blackboard with white chalk.
 
lawrenceSA said:
Thanks for your reply!

Would it be correct to say that there is an element of the white paint (base coat) reflecting light back to the observers eyes that almost washes out the light being reflected back to the observers eyes from the clear coat.

Whereas on a black car, no light is being reflected back to the observers eyes from the base coat (as black absorbs light) and thus the light being reflected back to the observers eyes from the clear coat is more easily seen, as there is better 'contrast'?

:help:
Click to expand...

probably depends more on whats in the basecoat, it isn't purely paint pigments, it has other things in it that cause the reflections, not to mention if it was a single stage black it would have clear mixed in with the base also.


but i would say that yes, that black basically gives more distinct reflections because you are looking at something with a background that isn't reflecting either.

i think the simplest way to explain the difference between black and white, is that the white washes out the reflections.

ie, black absorbs and does not reflect as much (or up to 95%, technically most paint codes for black have more than just black, ie, 202 toyota black has a very tiny amount of yellow in it. and codes for other blacks will have some blue or red, etc.)

but white itself reflects all.. the problem is that white that is so finely polished will appear... clear. reflects all colors but appears clear because there are no imperfections to cause the light to ounce around in. like how a block of ice that has no impurities in the forming looks clear, but a block of ice that has all kinds of imperfections and air bubbles will look almost white, the diffusing of the light source causes it to bounce around, looking white because it's reflecting all the colors and absorbing none.

the white paint of your car has titanium dioxide in it. the surface of it is trying to reflect all light sources back, but the rough and pitted porous nature of it at a microscoping level is causing the light to bounce around and diffuse on its surface rather than reflect, which is why it appears white instead of clear. your clear coat is actually white mostly, but so uniform and polished that it looks clear. if you were to scratch up the surface, it would then look white from the light being diffused on the surface.

which is back to why black makes a better mirror. the less light being diffused the better the reflected image from the clearcoat is
 
The black paint absorbs the diffuse light leaving only the reflection. White paint kicks back the diffused light as the color white. Because of the conservation of energy, the more light that is diffused, the less is reflected.
 
TurboToys said:
probably depends more on whats in the basecoat, it isn't purely paint pigments, it has other things in it that cause the reflections, not to mention if it was a single stage black it would have clear mixed in with the base also.


but i would say that yes, that black basically gives more distinct reflections because you are looking at something with a background that isn't reflecting either.

i think the simplest way to explain the difference between black and white, is that the white washes out the reflections.

ie, black absorbs and does not reflect as much (or up to 95%, technically most paint codes for black have more than just black, ie, 202 toyota black has a very tiny amount of yellow in it. and codes for other blacks will have some blue or red, etc.)

but white itself reflects all.. the problem is that white that is so finely polished will appear... clear. reflects all colors but appears clear because there are no imperfections to cause the light to ounce around in. like how a block of ice that has no impurities in the forming looks clear, but a block of ice that has all kinds of imperfections and air bubbles will look almost white, the diffusing of the light source causes it to bounce around, looking white because it's reflecting all the colors and absorbing none.

the white paint of your car has titanium dioxide in it. the surface of it is trying to reflect all light sources back, but the rough and pitted porous nature of it at a microscoping level is causing the light to bounce around and diffuse on its surface rather than reflect, which is why it appears white instead of clear. your clear coat is actually white mostly, but so uniform and polished that it looks clear. if you were to scratch up the surface, it would then look white from the light being diffused on the surface.

which is back to why black makes a better mirror. the less light being diffused the better the reflected image from the clearcoat is
Click to expand...

Awesome response man - thanks!

Makes perfect sense to me now :dblthumb2:
 
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