How It Works:

All Eltron plastic card printers feature the same basic printing operations; dye sublimation and/or thermal transfer printing. Both techniques involve heating a thermal print head while in contact with a ribbon. However, thermal transfer printing differs from dye sublimation in that thermal transfer uses ink rather than dye. In thermal transfer printing, heat melts the ink on the ribbon, causing it to transfer to the card surface. In dye sublimation, heat vaporizes the ribbon dye, which then permeates the plastic card.

The ribbon used in color dye sublimation printing is divided into three separate color panels Yellow, Magenta, and Cyan (see Figure 1). This configuration is referred to as YMC.These three colors are the primary colors used in printing to produce all other colors including black. The dye from the ribbon is applied to the plastic card via a multi-pass operation. This means the card will pass under the print head once for each of the three colored ribbon panels - applying each color separately."Dye Sublimation" is also referred to as Dye Diffusion. When the print head heats the dye on a ribbon, the dye is transformed from a solid to a gas and diffused onto the plastic card, which is specially coated to absorb the color dye.

The temperature of the print head controls how much dye is converted to a gas - as the print head temperature rises; more dye can be absorbed into the plastic card. Consequently, the picture quality and continuous color tones produced by a dye sublimation printer - at 300 dpi - can outperform most laser or ink jet printers with higher resolutions. The advantage of dye sublimation is the millions of colors that can be created. Varying the heat intensity on the ribbon panels yields various shades of each color, making color selection virtually unlimited.

As mentioned above, thermal transfer differs from dye sublimation in that it uses ink instead of dye. However, both dye sublimation and thermal ink (sometimes referred to as Resin) can be combined in one ribbon (see Figure 2). This ribbon is known as a YMCK Ribbon. The letter "K" designates the color black in the printing industry. Why do you need a separate black panel, when you can create black by mixing the three basic YMC colors together?

The answer to this question is simple. The black created by mixing the YMC colors together is referred to as "Composite Black." Composite Black typically looks muddy or has a grayish tint when compared to Thermal Transfer (TT or resin) black. Composite Black is not recommended for printing bar codes since it does not produce the sharp edge many scanners require. Although this is invisible to the naked eye, it is easily observable under magnification). Composite Black is also invisible to IR scanners since there is no carbon in the dye. Since you may not know what type of scanner will be used, the rule is to always use TT (resin) black to print bar codes.