Soft/spray encapsulation
PU (Polyurethane) coating
UCP - Ultima Coating Process
Laser etched keymat
Hard encapsulation
Polydome keymat
Metal dome
IMD - In Mould Decoration

A layer of soft coat is sprayed onto the surface of the button (inclusive of the side, above the web). 
Cosmetic appearance is gloss in appearance and printed graphics well protected.
Able to achieve complex profile of button if not constraint by the distant between buttons.

A layer of soft coat is sprayed onto the surface of the button (inclusive of the side, above the web) 
Cosmetic appearance is matt in appearance and printed graphics well protected.
Able to achieve complex profile of button if not constraint by the distant between buttons.

UCP - a vacuum deposition coating process for silicone rubber. It is capable of coating keymats with complex profile with a uniform thickness film for protection.
Material used in UCP is a transformation from parylene family offering unmatched coating protection.

Diagram shows the number of ink layers involved in a Laser Etched Keymat.

This method offers hard top feel as well as good cosmetic appearance.
All printed graphics are well protected by the hard epoxy coat giving good abrasion resistance.
Only constraint is unable to achieve complex top profile of knob.
There is no need to provide encapsulation top surface on CAD file.