Which metal is the most transparant to RF?

[SKU427]

I've heard that some metals are more transparent to RF than others.
ie: titanium and aluminum block less RF energy than steel and brass.
Is there a list or chart that lists the relative transparency of metals to RF?

 

[VEBill]

Electric field (works for HF RF too):

http://en.wikipedia.org/wiki/Faraday_cage

Magnetic fields at low frequency:

http://en.wikipedia.org/wiki/Electromagnetic_shielding

http://en.wikipedia.org/wiki/Mu-metal

For most applications it's not that critical. Many RF devices, even critical ones, are enclosed in an aluminum chassis that provides perfectly adequate shielding. The joints are typcally the weak point.

(Note: I'm using wiki links because it's convenient.)