Researchers in Sweden have developed a coded yarn-based tracking system that promises to overcome existing limitations and deliver improved traceability. In the new system, intelligent yarns are fully integrated into textiles during the manufacturing stage to produce traceability tags. The coded yarns contain special optical features and, as a result, create an optical stamp or pattern for traceability on the surface of woven or knitted fabrics. The tags are created by using a combination of coded yarns having different and distinguishable optical features or yarn classes.

Traceability is an ongoing concern for the textile industry. Technologies such as barcodes, QR codes and RFID tags have been put in place to enhance supply chain transparency but they often fail to provide complete traceability. The coded yarns work much in the same vein as barcodes, where lines of varying widths and spacing represent digits, and a set of lines represents the full code. Similarly, a coded yarn’s unique optical features represent a digit, with a sequence of coded yarns representing a complete code. The full code can be altered or controlled by changing the coded yarns’ sequence in the textile.

Barcodes and RFIDs possess low security against copying and reproduction, which means an identical tag can easily be reproduced and placed with a counterfeit. The tracking tags are removed at the point of sale. Therefore, it becomes difficult to trace back the history of a textile product after sale.