Sublimation printers allow us to print photo-lab-quality pictures. In dye-sublimation printing, colors are not laid down as individual dots, as is done in inkjet printers. Individual dots can be distinguished at a relatively close distance, making digital pictures look less realistic.
If you looked inside a dye-sublimation printer, you would see a long roll of transparent film that resembles sheets of red, blue, yellow, and gray colored cellophane stuck together end to end. Embedded in this film are solid dyes corresponding to the four basic colors used in printing: cyan, magenta, yellow and black. The print head heats up as it passes over the film, causing the dyes to vaporize and permeate the glossy surface of the paper before they return to solid form.
So the main difference between this and other types of printing has to do with heat. The vaporized colors permeate the surface of the paper, creating a gentle gradation at the edges of each pixel, instead of the conspicuous border between dye and paper produced by inkjets. And because the color infuses the paper, it is also less vulnerable to fading and distortion over time.
The dye sublimation inks are a pigment suspended in a liquid solvent, like water. The images are initially printed on coated heat-resistant transfer paper as a reverse image of the final design, which is then transferred onto polyester fabric in a heat press operating at a temperature around 180 to 210 C (375 F). Under high temperature and pressure, the dye turns into a gas and permeates the fabric and then solidifies into its fibers.The fabric is permanently dyed so it can be washed without damaging the quality of the image.
Advantages of dye-sublimation over other methods of textile printing:
- Images are permanent and do not peel or fade.
- Dye does not build up on the fabric.
- Colors can be are extraordinarily brilliant due to the bonding of the dye to the transparent fibers of the synthetic fabric.
- Truly continuous tones can be achieved that are equivalent to photographs, without the use special techniques such as half-screen printing.
- The image can be printed all over the entire item, with no difficulty in printing all the way to the edges.