FIRST,THERE IS NO SECRET. IT’S SIMPLY A MATTER OF UNDERSTANDING YOUR application(s), doing your homework, and using common sense.

That said, it’s not really quite that “simple” either. The good news, however, is that the most difficult part of the problem, understanding your application(s), is entirely within your control.

Standards
Many manufacturers and distributors will provide bar code shipping labels that conform to either EAN.UCC or HIBCC standards (which are the correct standards). Bar codes that conform to either of these standards are also known as UPN, or Universal Product Number, bar codes. However, many shipping containers and even inner packs have nonstandard bar codes. You will need to survey your suppliers as well as your own stock to determine which have UPN bar codes and which do not.

Understanding Your Application(s)
What and where? These are the first questions you have to answer. Where will you need to be reading bar codes? This will tell you what level of packaging you need to label. And the “what” will tell you “where.”

For example, if you want to track (scan) full shipping containers into the facility, you’ll want to label them in receiving.

If you want to track inner packs, they should be labeled at the point where they’re taken out of the shipping container.

Labeling unit-of-use medication might be performed in advance in a specialized repackaging room within the facility or in the pharmacy itself if bulk dispensers are used.

You should also consider whether other departments are considering bar code labeling. It might be possible to consolidate labeling activities for shipping containers or inner packs with other departments. This can reduce and improve overall efficiency.

Label size is the next consideration. Most printer types can handle a wide range of label sizes but you generally pay a premium for those that can handle wider labels.

If some, but not all, of your pharmaceuticals are bar code labeled, or if some have non-standard bar codes, you might want to produce the same size and type of label in-house for each packaging level to make it easy for personnel to identify the proper label to scan. If you are labeling shipping containers, you will probably want a larger label such as a standard 4x6 inch label. Inner packs might be labeled with a 4x6 inch label or something as small as a 1x3 inch label, depending on information requirements, symbology choice and available space for a label. Unit-of-use labels will probably need to be the smallest possible size, often no more than 1x2 inches—or smaller if the bar code will fit and can be read by existing scanners.

Durability is another consideration. How long does the label need to last, what are the environmental conditions (primarily light but also heat and abrasion), and where will it be read (what chemicals, such as isopropyl alcohol,
might spill on it)?

Volume. How many labels will you be printing per day, shift, and during peak times? A printer that can produce 20 labels per minute may seem entirely adequate if the requirement is for 5,000 labels per shift. However, it is wholly inadequate if you only have two hours to produce all the
labels for the shift.

Printer Options
There are two basic technologies to consider: thermal and laser. Both technologies can produce multiple copies of the same label with static data (such as NDC number) or single labels with dynamic data (such as patient ID or prescription numbers). Thermal printers can cost-effectively print a single label whereas laser printers are typically better suited to printing relatively large batches of labels, because the label stock has multiple labels per page.

Direct Thermal uses heat to physically change the color of the coating on the label stock. The direct thermal label stock should not be confused with the kind of direct thermal paper often used for receipts, which will very quickly fade if exposed even to body heat for several hours. Direct thermal labels can be printed that have good heat tolerance (certainly well within the range of temperatures at which pharmaceuticals will be stored), abrasion and alcohol resistance, and very good overall durability. The advantage to direct thermal is that there is only one roll of label material to change. The cost of direct thermal stock is equivalent to the cost of thermal transfer stock and ribbons so that is not a major advantage.

Thermal Transfer uses heat to bond a wax or resin image to the label stock. Resin-based ribbons offer superior abrasion and heat tolerance (when matched with the proper label stock) but can be easily damaged by relatively minor exposure to petroleum-based solvents. All thermal transfer printers can also be configured to print without a ribbon on direct thermal label stock.

High Output Lasers. These printers are designed for high volume applications and can be fed with fan-fold or roll-label stock. Typically, labels are printed two or more across (depending on label and stock size).

Desktop Lasers are suitable for some applications where volumes are not particularly high. This is attractive in some applications because they can serve as standard desktop printers as well.

Making the Choice
It is important to remember that a printer that is suitable for one application is not necessarily suitable for another. Although it is tempting to have the same make and model of printer throughout a facility, the result may be that you pay a premium for printers that are far more capable than the application demands, or you may run printers beyond their rated duty cycles.

When considering a printer’s duty cycle, never plan on running it continually much past 75% of its rated capacity. Printer vendors may argue that this is too conservative and that reliability is quite high but a small investment in “excess capacity” will help ensure good quality bar codes and provide a buffer for unanticipated demand increases.

It is also important to consider the criticality of any application, that is, how will a bar code printer going offline affect patient care? In applications where the bar code is critical, there are two options:

First, have two or more less expensive printers that can share the task so that, at worst, production will only decrease by 50% (although typically it would be less than that).

Second, have a “hot spare” ready to replace critical printers. The spare does not necessarily have to be as high quality as the printer it is replacing, but it should be compatible with the label design and database software.

For very low volume applications, it is even possible to use small desktop printers designed for mailing labels—as long as bar code software and drivers are available. However, even for low volume applications, it is advisable to choose a printer designed for bar code printing—and there are many available from a variety of vendors.

A Sticky Question
Printing bar code labels is one thing. But you also have to think about how you’re going to apply those labels—and this can affect your choice of printers.

For applications where the label will be printed, then applied immediately, volume is the consideration.

For high volume applications, a printer/applicator might be the best choice if the item to be labeled can be moved past the printer in a consistent manner. Printer/applicators are “industrial grade” printers that have a moving arm that takes the label and places it in a specific location on an item that moves past on some form of conveyor. They can be adjusted to handle a wide range of items.

For more labor-intensive but short-term applications, such as labeling in receiving, a print-and-peel option should be included. The backing is stripped from the label (and rewound in the printer) as it’s printed and the label is presented to the worker, making it a simple matter to take the label and apply it to a carton before moving it.

For bulk printing, there are label applicators designed to accept a roll of printed labels and apply them to items in the same way a printer/applicator does. The difference is that the labels can be printed ahead of time to smooth out label production schedules.

For sheet labels produced by laser printers, there are “peel and present” devices that will peel the backing away from the label, leaving just an edge attached, to make label application easier for workers.

Additional Considerations
Although the following recommendations are not criteria for selecting a printer, they are necessary to ensure a successful labeling program.
Purchase a verifier and verify your label production regularly. Verifiers are not the same as a scanner. They return specific quality grades for a number of parameters in accordance with ISO standards. Often minor adjustments to printers or software are needed to maintain good quality bar codes and a verifier will tell you where you might be experiencing problems.

When manually removing labels from backing material, always peel the backing away from the label. Peeling the label away from the backing induces a permanent curve in the label that can result in the label not adhering properly. When applying labels to curved objects, be sure the bars are perpendicular to the length of the item. Wrapping labels around a curve will render them unreadable. Clean your printers regularly. This is particularly true for thermal printers where the heat elements in the print head can get a fine layer of contaminants that can reduce print head efficiency and print quality. Cleaning kits are avail-
able and inexpensive.

Conclusion
Selecting a bar code printer, and printing bar codes, may seem intimidating at first. And perhaps it should. Printing good bar codes is much more complex than printing legible text, but once you understand the basics, the process will suddenly seem completely logical.

Bert Moore is the director of IDAT Consulting & Education, a vendorand technologyindependent consulting firm helping companies implement automatic identification and data collection (AIDC) technologies. Previously, Moore was the Director of Technical Communications for AIM, Inc. and has served on many national standards committees. He currently edits AIM’s “RFID Connections”, and is a contributing editor to Penton’s Material Handling Engineering magazine. He can be contacted at: 412341-1342 or bmoore@idat.com.