A thermal ink-jet pen which includes a tuned printhead for ejecting droplets of ink onto a print medium is provided. The printhead comprises (a) a plurality of resistive elements, (b) a plurality of nozzles through which the droplets of ink are ejected, (c) a plurality of drop ejection chambers, (d) a plurality of ink feed channels, each provided with an entrance defined by a pair of projections on either side thereof, and (e) an ink refill slot operatively associated with the plurality of ink feed channels, the ink refill slot defined by an edge to provide a shelf from the edge to the ink feed channels. The plurality of resistive elements is divided into sets, with each resistive element staggered a different distance from the edge. Each ink feed channel within a set is provided with a different critical dimension value, the critical dimension comprising at least one selected from the group consisting of (1) width of entrance to channel, (2) width of the channel, (3) length of the channel, and (4) distance of the resistive element to the terminus of the channel. The critical dimension is related to distance of the resistive element from the edge. By providing each set of resistive elements with different widths, the damping of the pen is improved and all the nozzles have substantially the same refill speed.