Keytops and overflow
Cut key
Hard-tops

Keytops serve various purposes in silicone keymat molding
(1)different hardness / durometer for a single knob
(2)defferent cosmetic colors for different knobs
(3)control over-flow or "bleeding" of color to neighboring knobs

Cul key has the advantage of allowing various versions of keymats to be molded out from the same tooling.

There are various ways of achieving a hard top button.
Co-mould (direct bonding)
Adhesive bonding
Plastic keycap insert
Hard encapsulation

The plastic is bonded unto the rubber with the help of primer applied on the plastic's bottom surface.
The plastic bottom surface must be made to a convex surface.
If button is circular in shaped and top profile is not symmetrical, a locator is needed to prevent the plastic from rotating during molding process.
Printing can only be on top of plastic surface.
Feasibility of this process is determined by the height of the button.

This method is direct insertion of plastic key cap to rubber keymat.
Gotada is able to design the internal details between the plastic and rubber fitting on your behalf.
All you need is to indicate the total height and flange height (if any). Gotada will design the fit and forward for your approval if required by you.

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.