Which is more stable? Carbon pill or Pinted conductive ink?

Silicone keypad always have a conductive pellet under the keys, close to the circuit layer side. This is the contact medium of the circuit traces on a Printed Circuit Board(PCB or FPC) or membrane switch, when pressed.

Normally the conductive pellet can be a golden pill, a carbon pill, or one layer of printed conductive ink. The conductivity character from better to worse is : golden pill>cabron pill>printed conductive ink.

The golden pill and carbon pill are molded together with the silicone raw materail in the tool, this makes the conductive pellet sticking very stable to the silicone, both materail combines into one materail.

While the printed ink are printed after silicone parts are molded and cool down, before printing the operator will clean the printed surface to ensure the ink will stick to the silcione material as strong as possible. But however strong the ink was printed to the silicone, both materail can't be combined close as golden pill or carbon pill.

And when end user press the keys, the actuation force will break the adhesion of ink and silicone, but that wouldn't happen to the golden pill or carbon pill.

Obviously from the point of stability, carbon pill will be better than the printed conductive ink.

More, following is the comparison chart of circling life of the different conductive pellets:

Carbon pill has 1, 000 times of the printed ink, do you still want to use the printed ink nex time, when the supplier suggests to?