Some Laser etched Silicone Rubber Keypad ( for backlight ), which silicone buttons surface is even, also process by silkscreen printing, not by color coating for save manufacturing cost. but rubber buttons R angle can't be printed, and aslo flat silicone buttons need at least twice silk screen printing for enough shading.
When the keypad surface is uneven with curved surfaces, it should use Transfer Printing process.
Conductive Printing Silicone Rubber Keypad
Xiamen Better Silicone Rubber Co., Ltd is specialized in producing silicone rubber keypads used all kinds of technology and surface protective treatments. For instance, silk screen, laser etching, epoxy, dual durometers/colors, plastic rubber, metal dome and PU coating, etc.