The discussion on anodized aluminum plates came from a question about making
photographic prints on metal. I had run across some material while researching
the anodizing process, that talked briefly about sensitizing the oxide layer
with a light sensitive compound such as silver nitrate. Shortly after that, I
found a photographer on the Compuserve system who had actually made some
photographs using plates sensitized by the Metal Photo company.
On the more practical side, most aluminum products have been anodized since
aluminum is very reactive and oxidizes rapidly. The metal tags with the serial
numbers on the back of many electronic devices are actually made using the Metal
Photo process. The aluminum housings for cameras and telescopes are often black
anodized. In fact, the process I posted here mostly came from information in an
amateur telescope making book.
Hope this helps.
- Wayde Allen