A printer is provided for printing, onto a surface, an interface of visible data and invisible coded data. The visible data is based at least partially on document data which includes identity data indicative of an identity associated with a region of the interface. The printer comprises an actuator, a coded data generator configured to generate the coded data based at least partially on the identity data, and a printing mechanism. The printer is configured to print the interface onto the surface by printing the visible data and the invisible coded data substantially simultaneously, using the printing mechanism, in response to actuation of the actuator.