They're typically made of a metallic weave that can include carbon, lead and potassium.

FORBES: Shield sham

Typically they are made of a metallic weave that can include carbon, lead and potassium.

FORBES: Shield Sham

Some kind of organic metallic alloy stronger than titanium or carbon steel, harder than diamonds.

NPR: Summary Judgment: 'Fantastic Four,' 'Dark Water'