A method of producing batches of micro particles includes affixing a substrate sheet to a support and cutting the substrate sheet with a laser device to define a plurality of micro particles. Before, after or during the cutting of the substrate sheet, the region of the substrate sheet defining each micro particle is marked with a code or other identifying marking using a laser device. The code or other identifying marking is unique to the particular batch of micro particles to uniquely identify that batch. The micro particles are removed from the support by a solvent. Preferably, a single laser device is used for cutting the substrate sheet and marking the micro particles. Alternatively, separate laser devices may be used for cutting the substrate sheet and marking the micro particles.