Andrew VK3BFA wrote:

Hey - I long ago gave up looking for rationality in these things -
just view it as an opportunity to get some nice thick aluminium
plate.......

Andrew VK3BFA.

We have some "sign" material at school and I went to use a bit
of it some time ago. What a pain to get the plastic coat that
contains the color/text off. That must be the ultimate atach
method. The aluminum was pretty soft and the plastic was almost
stiffer than the metal. :-)
...lew...