On Mon, 26 Jan 2009 22:26:58 -0500, "NoSPAM"
wrote:

Titanium dioxide is a very bright white. It reflects the ultraviolet, as
well as visible and near-infrared.
(...)
Carbon black is added as an absorber of ultraviolet.

So, the difference is that titanium dioxide reflects UV, while various
black pigments absorbs UV. Ok, that makes sense. Thanks.

I would bet that red PVC tape lasts for only a short time in sunlight.
Most organic red pigments are destroyed rather quickly by ultraviolet
light, a real problem for automobile paint. There is a reason for Clear
Coat beyond its looks!

Yep. One of my non-clever neighbors painted their house candy apple
red. Besides being rather garrish, the paint lasted about 2 years
before fading rather badly. They had to sandblast and re-prime in
order to start over with basic beige.

Incidentally, one of my former neighors was a painting contractor. He
painted his house with the left overs from various jobs. None of the
colors matched. Not exactly an eyesore, but close.

I have some red electrical tape. I'll give it a try on the roof and
let you know after summer.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558