RFID-Labeling Apparel Items

By Ken Traub

Here's how to set up your printer-encoder software.

  • TAGS

Increasingly, apparel retailers are adopting RFID, and they are asking their suppliers to tag items at the source of manufacture using EPC Gen 2 ultrahigh-frequency tags. Each tag is encoded automatically by printer-encoder software, but suppliers must first set up the software by inputting information about each product and their company—or, if they are outsourcing RFID-tagging, provide that information to their label provider. Here’s the information you need, along with the steps you should follow to obtain it.

Determine your Global Trade Item Number (GTIN). This is a 14-digit number that is unique for each product and identical for all instances of the same product. If your product carries a Universal Product Code (UPC) or European Article Number (EAN) bar code, simply take that number—12 or 13 digits, respectively—and add one or two zeros to the left to create a 14-digit GTIN. If a private-label product doesn’t have a GTIN, contact the GS1 standards organization to get one.

Determine what portion of the GTIN is your GS1 Company Prefix. The middle 12 digits of a 14-digit GTIN (excluding the first and last digits) are composed of a GS1 Company Prefix followed by an item number. The number of digits in a GS1 Company Prefix can vary from six to 12 (with the length of the item number varying inversely), and your encoding software will need to know how many digits it is in order to encode the GTIN into an RFID EPC tag. The person in your organization who assigned the bar-code number should know your Company Prefix; if not, contact GS1 for assistance.

Choose a serialization method. In addition to the GTIN, each RFID EPC tag for a given product contains a unique serial number. Your encoding software will assign the serial numbers automatically, but you need to choose an assignment strategy that fits your business. See my columns “Identifying Items” and “Serialization Roadmap,” or the guide “EPC-enabled RFID Serialization Management for SGTIN-96,” available from the GS1 US Web site.

Once you start producing tags, do some spot checks to verify that your RFID EPC tags are readable. It is especially important to confirm that the GTIN and serial number are encoded correctly. The free encoder/decoder tool at www.kentraub.com/aidc can help with this.

You must repeat these steps for each product you tag. At first, this may seem like a lot of work. But many or all of your products likely share the same GS1 Company Prefix. Also, if your products share a similar manufacturing process and volume, you will probably use the same serialization method. In those cases, after the first product, all you need to determine is the correct GTIN for each subsequent product.

Ken Traub is the founder of Ken Traub Consulting, a Mass.-based firm providing services to software product companies and enterprises that rely on advanced software technology to run their businesses. Send your software questions to