Dye Sublimation Printers

"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.

In general, all dye-sub ID card printers are capable of printing in monochrome using a single color ribbon. These ribbons are less expensive than full color multi-panel ribbons and can be either dye or ink (thermal transfer). The most commonly used monochrome ribbon is "Black" but there are several other colors available including; Red, Green, and Blue.

Dye Sublimation ribbons are preferred for printing pictures for photo id cards or security badges, since they can produce many shades of gray for a smoother look and a better picture quality. A resin black picture normally uses a dithered gray scale (gray made from a combination of pixels which limits the number of shades), producing a coarser, grainy look to the image.