Anodised aluminium is a lightweight metal which can be used both inside and outside - it is engraved and can be paint filled with a colour to contrast the background if required.
Aluminium can be powder coated to change the background colour to meet your requirements. The borders, emblems and letters are engraved by removing the paint to display the silver below.
Suitable for outside use however as it is a "softer" material it is prone to scratching, vandalism and eventually the background paint will fade.