In 1957, NoŽl de Plasse, a researcher working for French textile company Lainière de Roubaix, made an interesting discovery. He found that, under high temperature, certain solid dyes could pass directly to the gaseous phase without first becoming a liquid. This physical process is called sublimation.
†Today, dye-sublimation printing has become a popular and versatile process that is predominantly used for various types of textile printing, but also rivals UV for printing on three-dimensional objects like mugs, smartphone covers, and other specialty items.
A dye-sublimation ink consists of a solid pigment or dye suspended in a liquid vehicle. An image is printed onto a transfer paper—also called release paper—and the paper is brought into contact with a polyester fabric using a heat press. Under heat and pressure, the solid dye sublimates and suffuses into the fabric, solidifying onto the fibers. The image physically becomes part of the substrate.
For years, printing via a transfer medium has been the standard dye-sub method. However, there have emerged systems—called direct dye-sublimation or direct disperse—that can print directly onto a fabric without requiring a transfer sheet. It's tempting to think, “Aha! Now I can save money on transfer paper,” but it's not quite as simple as that. Both varieties of dye-sub have their advantages and their disadvantages, and if you're new to the technology, or are looking to invest in a dye-sub system, it pays to understand the benefits and limitations of each.
With transfer paper, during sublimation, the ink doesn't penetrate far into the substrate, remaining close to the surface. In contrast, direct disperse penetrates further into the fabric, which—much like inkjet printing on plain paper—means that fine detail is lost and colors become less vivid.
Another advantage of using a transfer process is that you can work with any kind of surface with a polyester coating: banners, mugs, flip-flops, you name it. “There are so many applications, and that's really the benefit of a transfer process,” said Check. “It makes it a very versatile solution.”