With the holidays, it looks like I won't have paint for awhile.....don't get me started on UPS. Why does it take only three days to have a plane on my doorstep from France that had to go through customs that is several thousand miles away and it takes seven to eight days for a box of paint from California that is 800 miles away!

OK, let's cover a few more basics while I wait for paint.

Let's go over the two main groups of paint.

The first is what is called "single stage". Single stage requires no clear to be shot on top. The clear is basically part of the paint.

The next group is usually known as "base coat, clear coat system" or "two stage". This system is used on virtually all factory automobiles that I know of since the late 80's. This system uses a color base with a clear coat shot on top. One reason they dominate the auto industry is due to UV protection. In a single stage paint, there are limits of how much UV protection can be built into the paint. The bottom line is two stage systems typically have a longer life expectancy versus single stage.

The question is "why would I use a two stage system when I could save time, money and maybe some weight and use a single stage paint"?

It all comes down to "reflection" versus "refraction". Those are two extremely important terms to describe how we view paint.

In a single stage paint, when the sun hits the surface, the gloss is "reflected" back to our eyes. You may say, "well of course it is", but there is an important aspect to be aware of. You see because the clear is basically the paint, the suns rays do not penetrate the gloss surface so all we see is the base color and a gloss reflection.

Conversely with a two stage system, the clear coat(s) are on top of the base coat. So when sun rays hit the surface, they are not immediately reflected back, rather they penetrate the clear coat and any transparent coats on top of the base and then exit the clear back to our eyes. Another way to think about it is the rays penetrate the clear, bounce around and then exit the clear. The term for this is "refraction".

Refraction is what gives us "depth" to a paint surface. When we use a transparent paint system, you can see that exceptional depth can be achieved as the sun rays penetrate the many layers of paint. The refractive property can actually be measured in what is called the "IOR' or Index of Refraction.