Dye sublimation is a digital printing technology that offers better resolution and color than ink jet printing. Here is how it works.
Sublimation is the change from a gas to a solid, or vice versa, without going through a liquid stage. In a dye sublimation printer, the dye begins as a solid. Each printer has three solid dye ribbons, for cyan, magenta, and yellow. The ribbon is pressed against a sign by a large printer head.
The printer head has hundreds of pinpoint-small heating elements, each of which can be heated and cooled extremely rapidly. As the sign moves under the printer head, these heating elements flash on and off. The hotter an element flashes, the more dye is sublimated.
The dye sublimates to gas, but then cools almost immediately into solid, permanent colour on the sign.
A dye sublimation printer puts down a layer of blue dots, then a layer of magenta dots, and then a layer of yellow dots. Because the dye dries instantly, the printer can put dots of different colours on top of each other without smudging the sign.
Dye sublimation printers finish this up by laying down a sheet of plastic laminate and using low heat to fix it to the sign. This is necessary because it prevents sunlight from sublimating the dye back into gas. The laminate is thick and strong, and dye sublimation prints tend to be much more colour-fast than ink jet prints.
Dye sublimation produces a much better end product than ink jet printing. In ink jet printing, the printer head only moves over the print once. For each dot, the printer head decides to use cyan, magenta, or yellow ink. As a result, each dot can only have one of three colours, and can only be of one tone of those three colors. Because the ink is liquid, the printer cannot add more layers of color without smudging the sign.
As a result, the different colours and tones of ink jet printing are just optical illusions caused when the human eye “summarizes” hundreds of different dots of cyan, magenta, and yellow. However, the illusion is far from complete. Ink jet pictures have a messy, granular quality that looks especially terrible on larger prints and signs.
Dye sublimation, on the other hand, can make each and every dot a precise colour and tone. This is known as continuous-tone technology. Dye sublimation particularly shines in images with large blocks of color. These look clean, crisp, and professional.
As a final note, dye sublimation prints are finished the second they come out of the printer. They are clean, laminated, and ready to go outside. By contrast, ink jet prints come out of the printer soaking wet, giving more time for the ink to run or smudge.
For these reasons, most respectable print shops choose dye sublimation printing for all of their large sign printing work.