The three most common uses for RFID tags are:

1. Tracking items in production lines

2. Tracking items in supply chains

3. Enhancing security measures

In other industrial uses, tags attached to items for tracking during assembly or manufacture must be able to withstand heat, cold, etching processes, cleaning and degreasing procedures, moisture, dirt, and many other types of conditions and environments that would not be suitable for optically or magnetically read devices.

With many types of digitally printed applications the user is unaware of the existence of the chip and antenna because of the different methods of concealing them on the document. Some producers of digitally printed applications (such as label printers) purchase inlays (containing the RFID) that are already manufactured and then they incorporate them into their printed products.

One of the fastest growing segments of the digital printing industry, in which RFID technology is incorporated with printed documents, is label printing. Smart labels and electronic surveillance labels are being used for applications in which simple, optically read barcoding may not be suitable.

Smart Labels

Digitally printed smart labels contain RFID transponders which are use to automatically capture data. The standard construction of a smart label consists of a pressure sensitive facestock, an inlay, which contains the radio frequency identification transponder, and a liner. The inlay is laminated between the facestock and the liner. The transponder contains an antenna and microchip.

The data from the smart label is accessed when the transponder in the label passes near the reader. Radio waves from the reader are received by the antenna in the RFID and the data on the microchip is transferred back to the reader and is then passed on to a computer or printer. As the product moves from one stage to the next, its movements can be monitored and data can be updated when necessary. The smart label can identify a product, track in real-time, and authenticate a product.

Smart labels are used on all types of applications including supply chain management, production control, work-in-process, baggage identification and tracking, express delivery services, reusable container tracking, and security systems. Several types of equipment are used for encoding RFID inlays:

• Equipment is available that is capable of encoding a separate RFID inlay and then bonding it to the substrate after the label has been printed. A variety of label substrates can be used. This process eliminates the need for inserting transponders into blank label stock before the label stock is printed. Since the printing process can damage stock containing transponders, the process eliminates this potential problem by allowing the printing to be completed first. This creates a printing system that is on-demand. There are no requirements for the use of special papers because the equipment is capable of printing on almost any label stock.
  
  
• Some types of equipment are capable of encoding data on very thin UHF RFID transponders that are inserted into smart labels. The equipment immediately verifies the proper encoding. The equipment can then print text, graphics, or barcodes on the smart label to complete the application. The smart labels can be used for a number of warehousing, inventory, and supply chain tracking applications.
  
  
• There are also compact digital desktop printers specifically designed for RFID printing. The printers can read, write, and print labels that have an embedded RFID transponder.

Electronic Article Surveillance (EAS) Labels

EAS labels are used as antitheft devices. The label is used with EAS monitoring equipment for detection of the removal of items without authorization. The EAS systems are used in retail stores, data centers, and libraries. When applied to products, the EAS label is capable of activating an alarm as it passes through an electronic surveillance detector, such as those found in retail store exits. When the product is purchased, the label is made inactive by the use of a deactivation device at the checkout station. Once the label is deactivated it is referred to as a dead label. Labels that have not been deactivated are referred to as live labels.

RFID is only one of the technologies used for EAS labels. Other common types are AM (Acousto Magnetic) and EM (Electro Magnetic). Each of the EAS systems has its own unique detection equipment that must be used in order for the system to operate properly.

Because of the antitheft protection they provide, EAS labels and EAS systems allow more freedom for retail stores to display items that would usually be locked in display cases. This allows the consumer to examine the product closely before purchasing.

RFID and barcode technology are similar in concept, but the two technologies have different methods for reading data. RFID systems read data via radio waves and do not require a direct line of sight between the reader and the tag. Barcodes are read optically and do require a direct line of sight between the reader and the barcode.

Advantages of RFID systems over barcodes:

• It is not necessary to have a direct line of sight between the RFID tag and the reader.
  
  
• Information can be added or rewritten to rewritable tags without having to see the tags. This is true even if the tag is mixed with other items that have been tagged.
  
  
• Nearly 100% of RFID tags remain readable in harsh conditions and after rough handling, unlike items that containing printed barcodes, which can become damaged with improper handling.
  
  
• The potential problems associated with substandard print quality of barcodes, which in turn leads to scanning and reading problems, are eliminated when using RFID technology.

Other points to consider:

• Barcodes are universally accepted because they are very inexpensive and there are established standards for their use. RFID technology is more expensive and has fewer universal standards in the methods in which they are used.
  
  
• RFID technology may never totally replace the universally accepted barcode technology.

Systems are now available that provide RFID technology for digitally printed documents without the requirement of a microchip. Some of the systems involve the use of aluminum fibers, which are embedded into paper or packaging materials. The fibers reflect a signal that a computer interprets as data.

Another chipless system involves the use of materials made up of very small chemical particles that possess varying degrees of magnetism. The chemical particles become active when exposed to the electromagnetic waves from a reader. Each of the chemicals emits a unique signal that is received by the reader, which interprets the signal as a binary number. The system uses as many as 70 different chemicals, so there are 70 different signals. Each chemical has a specific position in the 70-digit number, which means that a unique binary number can be assigned to a document based on the mixture of chemicals that are used.

The small particles can be embedded in paper or they can be printed onto paper or almost any type of substrate. Printed barcodes can be created, which can be scanned from up to 10 feet away without the need for the barcode to be in line of sight of the reader. With slight modifications, this technology can be used with existing barcode systems, which helps to limit the cost in developing a system since major upgrades of equipment are not necessary. The only types of environments where the system does not work very well are in areas containing large quantities of water or metal objects. Water absorbs RF signals and large quantities of metal reflect the signals.

Other security measures that can be used in conjunction with the system are:

• Digital printer/copiers can be fitted with readers to prevent unauthorized copying.
  
  
• Some RF applications could be used which would require that a document be photocopied onto the same type of paper as the original.
  
  
• Any institution wishing to protect documents could install readers at all exit points in the building, which would detect if any unauthorized persons were attempting to leave the building with an original or copied document.
  
  
• The system can also be used for counterfeit prevention and for tracking manufactured products.

Besides the various types of RFID labels that are being printed for product tracking and security, plastic cards and badges (laminated digitally printed applications) embedded with RFID transponders are being produced. Data from identification cards embedded with RFID tags can be read as people pass through a doorway. RFID tags embedded into security badges offer an alternative method for controlling access to sensitive information or limiting access to specific areas.