A clock data recovery circuit including a recovery unit and a loop control unit is provided. In general, an ink source comprising a saturated zone and a tubarc porous microstructure for conducting ink from the saturated zone to an unsaturated zone are provided. Having the chambers of adjacent levels being arranged to communicate with one another regardless of the relative orientation of the levels permits any one level to be rotated about a vertical axis in relation to the other levels as well as permitting a plurality of different stacking orders to produce numerous different combinations and different solutions to the maze structure. A feed-forward control reference andor sensitivity vector may also be calculated as a function of the target thickness profile, and used in generating the control signal sent to the control device.