paint pigments

I recall a little discussion about the size of metallic pigments/flakes in paints but can't for the life of me remember where that was or find the thread again.

Quite simply, are the metallic flakes in tamiya sprays in scale?
i.e smaller flakes/pigments?

What I mean is, I've seen a lot of very nice metallic paints at halfords but using my own car as a reference, the metallic flakes do seem bigger than what I get from a tamiya TS spray. Would it be noticably different, scale-wise, if I used the automotive metallic on a 1/24 car?

How about automotive pearls and Mica paints?
Moving onto mica paints for a while, is that a metallic paint with ground Mica flakes in it as well or is it a semi-transulcent paint with Mica flakes? Are the Mica flakes in Tamiya TS sprays also smaller then those in Automotive sprays?


DM (enjoying the sun - hating the pollen)

Metallic particles come in many different sizes in automotive paints. Some are refined enough to translate very well for modeling purposes while others contain larger particles that, when used on a scale model, look "out of scale".

"Scaling down" metallics, however, is not possible without altering the color of a finish. For example, if you had 4 ounces of a paint color that contained 1 ounce of 24 micron sized metallics and instead you used 1 ounce of 1 micron sized metallics, the smaller metallics would distribute more evenly through the color and change it. It's sort of like dumping a spoon of powdered Nestle Quik in a glass of milk - without stirring it, some of it will sink, some will float in chunks, and although the milk may look tan in areas, overall you'll still have a glass of basically white milk containing dark areas of chocolate. Stir it, and the large lumps of dark chocolate break down and distribute through the milk and everything becomes uniformly brown.

Replicating an authentic factory metallic or pearl finish on a model can only truly be done by using the actual factory finish. If you want a more realistic metallic or pearl appearance you'll have to choose a finish that is more refined to begin with.

Mica is another term for pearl. To generalize, most metallic particles in paint are made from different sizes of aluminum flake, and most pearl pearl powders are simply the same aluminum flake that's been colored or tinted and is usually more refined.

right.
thanks for that.
I was always under the impression that they actually used Ground Mica particles/flakes in mica paint, hence the name.

So, the short of it is that the size of the flakes is dependent on the paint and that there is no standard. Guess that means a lot of staring at random passing cars then.

thanks again.

Hey DM,

Firstly, I haven't posted for ages, but have been looking around and have enjoyed builds and discussions mentioned, well done to everyone, and keeping the forum so active. It's always refreshing to see posts, and this is one of those interesting posts.

I have always wondered the same too DM. I haven't built much but colour is my favourite part of a model. I have been trying out some paint for some time now and also making comparisons by trial and error, and advice from others.

http://files.automotiveforums.com/gallery/watermark.php?file=/503/166954grey.jpg

The pic above shows some metallic greys which I really took a fancy to while in Halfords some time ago, and can say the pigments are really small, haven't tried on a body yet though. But while spraying some bodies yesterday, the Halfords paint spreads pretty good too, plus there is such a wide choice of colours to choose from instead of the Tamiya TS sprays.

Metallic paints I find the most interesting because of the depth and finish, and recently tried shooting pearl automotive paint. Knowing that some colours might not be to scale, but making a choice by seeing the real thing, and advice from professional body repairers. I managed to get hold of some original Verde Artemis, PPG for a Murcielago 40th anniv. a week ago, but only had time to shoot during the weekend. As you can see below, the pigment is super fine. The body is coated with a peppermint ground coat first, then a recommended 4 coats of the basecoat. Seems a bit dark, gloomy afternoon and no clear at the moment.

http://files.automotiveforums.com/gallery/watermark.php?file=/503/166954verde40th.jpg

The rain this afternoon has meant I couldn't shoot some 2 part clear. but hopefully will try for this weekend. This colour is really nice in person, I will start a thread for this build soon.

Unfortunately, my approach to colour is trial and error, but it's the joy of the hobby, and what has made me start again. Colour!!! YAY!!

Thanks Leon, great useful answer. So in other words you're saying that ground to scale, metallic flakes would start to act less like a particulate reflective medium and instead would get combined into the paint more like a pigment? It helps not to have a reason to worry about flake scale size in paint.

So metallics, pearls and micas all tend to use aluminum flake as a reflective agent? I've wondered if there really is much difference between a color labeled 'metallic' or 'pearl'. How do transparent pearl finishes work- just fine ground tinted aluminum flake in a transparent carrier?

Not so much that the particles would be masked by the paint, but rather the two separate elements would become less distinctive from one another. Like a white circle in a red square, each color is very strikingly different, but if you divided the white circle and spread it across the red, the overall color of the square would increasingly begin to look pink as you continued to divide and distribute the white over the red. Without adding or subtracting anything, you would change the overall color appearance merely by resizing the components.

Transparent pearl finishes are typically associated with tricoat finishes where the pearl midcoat, either clear or tinted, is applied over a basecoat color. There's still quite a bit of difference between pearls and metallics since pearls can be a different color than the paint they're in (like gold pearl in lime green paint) for a range of combinations whereas metallics are usually only silver.