Print path planning and nozzle offset design for multimaterial lattices

Non-printing travel moves are a major source of inefficiency and defect formation in additive manufacturing. Their impact is becoming increasingly pronounced as printhead designs and multimaterial printing capabilities continue to advance, especially in architected multimaterial lattices, where disconnected features and frequent material transitions can cause excess deposition, interfacial defects, and air entrapment during printhead jumps. Here, we cast print path planning as a graph-based rural postman problem and develop a constructive heuristic that lexicographically prioritises minimising jump count before minimising total jump distance. Unlike distance-first strategies, the proposed approach directly targets the manufacturing cost of travel moves by reducing opportunities for defect formation and process interruption. We further extend the method to multi-nozzle printheads with fixed offsets and show that printhead layouts can be tailored to the target geometry. This enables printhead co-design that further reduces jump count and jump distance, particularly for periodic substructures and high-throughput production. We validate the method experimentally using direct ink writing and discuss its broader applicability to material extrusion and other additive manufacturing processes.