There was a time when field-printing digitized images on plastic cards was not for the faint of heart. In the early 1990s, $100,000 could buy 4 non-networked photo-capture and print stations, churning-out black and white images and text onto plastic cards. In-line magstripe encoding? No. Duplex printing? Think again. Crystal-clear color photo’s and high resolution artwork? Not yet.

Further, the corporate and university campuses, theme parks, and other early-adopters had their hands full with operational and technical challenges. What a difference a decade makes. It is a testament to the reliability of modern ID card printers that few need to understand how they work. The fact is, they typically work so well we don’t have to know how. However, as any mid- to high-volume user of personalized cards will tell you, a little understanding can go a long way when cards must be printed and a printer has broken down.

Many contactless cards arrive at the card issuer–the financial institution, the transit agency, or the corporate site–fully printed and ready to distribute. The graphics are on the front and back and the data is encoded into the contactless chip. But just as frequently, they must be customized, personalized, encoded, and/or printed. When cards are personalized to the cardholder, as in the case of corporate ID badges–an onsite printer is frequently utilized to add the cardholder photo, name, and pertinent information to the plastic card. In this article the process for printing and personalizing contactless cards is examined.

The process used by most card printers today is called dye diffusion thermal transfer or dye sublimation (dye sub). It involves the transfer of dyes from a ribbon to a plastic card via heat. The key pieces of this process are the print head and the ribbon.

The base for a dye sub printer ribbon is a thin, but durable, plastic sheet called a carrier film. The carrier film is stained with a waxy substance containing the dyes. In color processes, the ribbon has a series of different colored panels which, when combined in specific amounts on the card, create the full spectrum of colors. The printer applies the dye from these panels, one pass at a time. Most ribbons utilize four panels for applying images and text–cyan, magenta, yellow, and black–and another clear panel that serves as a protective overlay. With these distinct color panels, all colors in the visible spectrum can be created.

To envision the process, think of a painter mixing colors on a palette. A certain portion of cyan mixed with yellow will produce a green hue. Add more cyan and an aqua will emerge. The key is in how are the colors applied in different and controlled proportions. The answer leads us to a discussion of print heads.

The print head is the means by which the heat is applied to the ribbon, at specified locations and at specified temperatures, to produce the intended color transfers to the card. A typical print head consists of 6 separate heating elements per millimeter. Each element is capable of producing 256 temperature variations. Each variation transfers a corresponding amount of dye from the ribbon to the card. Thus, to answer the question above, a mid-range temperature from an element transfers a mid-range intensity of dye from the color panel to the card.

Each element creates or transfers dye to a single pixel or dot. Most card printers in use today print at 300 dots per inch (dpi). This means that in every square inch of card space, there are 9000 individual pixels (300 x 300). To create the accurate color specified in an image, a pixel may need dye from all three (or more in four and five panel ribbons) separate panels. As you can see, the printer must be a highly precise and reliable piece of equipment to control this process.

When printing on contactless cards there a two keys to remember:

•  First, make sure that the card’s plastic stock is designed to accept dye sub printing. Certain plastic card compositions print well (e.g. PVC) while others do not (e.g. ABS). A new breed of printer is available that prints the image onto a clear piece of film that is then adhered to the plastic card. This “retransfer” process enables the personalization of ABS, PET, and other card types previously not printable via dye sub processes.
•  Second, check with the card manufacturer to determine how best to print your specific cards. Some manufacturers will not warrant contactless cards that were printed in an unapproved manner. Following their guidelines will also help ensure a quality output by instructing the artist /designer where to and not to place images to avoid the embedded antenna.

Card printers are manufactured by a number of companies including Fargo, DataCard, Eltron, DaiNippon (DNP), and a handful of other makers. While most manufacturers will sell direct to end users, issuers frequently obtain printers via system integrators or resellers.

Each manufacturer offers a series of models with different feature sets. The key features to consider include:

Contactless chip encoding
More and more printer manufacturers are offering the ability to encode data to a contactless chip during the print process. This can save valuable time and keep confusion to a minimum during a high-volume issuance. Models for HID’s iCLASS™ and Philips’ Mifare® are available from multiple manufacturers as are models that encode ISO 14443 Type B, ISO 15693 cards, LEGIC, Sony’s FeliCa™, and other contactless and proximity technologies. Check with your system integrator or with the card printer manufacturers for details.

Print speed
How much time does it take for the printer to accept data and produce a finished card? Be aware that the time listed by the manufacturer can vary greatly when placed in your operating environment. Talk to users of the printer to get their impression of the actual print speed.

Duplex printing capability
This is the printer’s ability to print both sides of a card in the same print cycle. For many issuers, this feature is unnecessary as the back of the card will be preprinted by the card supplier or via another print station.

Magnetic stripe encoding
Nearly every printer has this capability but it is not always included in the price of the printer. If you will need this functionality, make sure to find out if this module adds any additional costs to the unit.

Contact chip card encoding
Some models offer a contact chip encoding module to enable card encoding during the print process.

Card sizes accepted
Will the printer accept only CR80/ID1 cards (standard ID size) or will it also print other sizes? Some card issuers print badges for seminars and events on larger cards or dedicated access cards on smaller stock.

Edge-to-edge printing
In the past, desktop card printers could not print images that extended all the way to the edges of the card. These cards had a thin white band around the card. Today, many printers offer this full-bleed or edge-to-edge capability enabling more flexibility in the design of the card. Additionally, “retransfer” printers enable edge to edge printing with no wear on the delicate print head.

Footprint/size
Depending upon the size of your card issuing facility the physical dimensions of the printer can make a difference in your workspace. Very compact printers are available today as well as the traditional large, heavy units.

Printer drivers
Ensure that the printer drivers (software) required for the specific printer you are considering are available for use with your card production system. If the drivers are not freely available, do not assume that the price to purchase them will be inconsequential. Some drivers can cost more than the price of a low-cost printer.

Price
The price range for dye sub printers is extremely broad ranging from less than $1000 to more than $20,000. Examine your individual needs in terms of throughput and functionality before shopping for a printer.

A great way to begin the shopping process is to talk with integrators, vendors, and end users. Manufacturer web sites are also a great resource for comparison information but remember that the best information often comes from peers who are actually using the printer. If you are looking for reseller sites, visit the following sites for more information on card production systems and services:

• www.colorid.com
•  www.visiondatabase.com.

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Related articles:

Select printer ribbons based on application Dye sublimation printing: Putting images and text onto plastic Understanding the card imaging process helps in printer selection