This disclosure describes a keyboard that is selectively configurable in a testing mode, where characters are not visible on a set of touch-based input receivers of the input device, a training mode, where characters are visible on some but not all of the set of touch-based input receivers of the input device, and a standard mode, where characters are visible on all of the set of touch-based input receivers of the input device. This disclosure also describes techniques for manufacturing the input device and illuminating characters via the touch-based input receivers. The described keyboard improves on conventional input devices by allowing selection of one or more touch-based input receivers for which characters are illuminated, or selection of a testing mode where a user cannot see characters on any of the touch-based input receivers.