A printhead suitable for minimizing cross-contamination between nozzles is provided. The printhead comprises a substrate, which includes a plurality of nozzles for ejecting ink droplets onto a print medium. Each nozzle has a nozzle aperture, which is defined in an ink ejection surface of the substrate. The printhead also comprises a plurality of formations on the ink ejection surface. The surface formations are configured to isolate each nozzle from at least one adjacent nozzle, and typically take the form of enclosures surrounding each nozzle.