Produce is often packaged in clamshell units. Such clamshells provide retailers and restaurant operators with a standardized merchandizing unit, offer brand owners a labeling opportunity, and offer convenience to the consumer. Clamshells are typically manufactured using a thermal forming process. Following their manufacture, clamshells are typically nested together to save space and stored in bulk containers.
Adding traceability to item-level produce requires putting a unique code on each package, such as each clamshell. In some prior art implementations, codes have been added with an inkjet system. Problems with the use of inkjet systems to mark codes onto clamshells and other packages include (a) inkjet systems require considerable maintenance, (b) codes tend to be poorly printed and therefore difficult to read, and (c) typical inkjet systems cannot reliably print small barcodes, and barcodes are needed for automated scanning such as along the distribution chain, in stores, or anywhere one has a mobile phone configured with a barcode reader.