Transfer or Direct Disperse Dye-Sub Printing: Which is More Sublime?

In 1957, Noël 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, and what de Plasse had discovered was eventually termed dye-sublimation. Nothing much was really done with dye-sublimation until the late 60s, when it began to be used in early computer printers. 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.

The big benefit of using a transfer process is image quality. “You end up with a more detailed image, the edges are a little sharper, text is much more crisp and sharp, and colors are more vivid,” said Tim Check, Product Manager, Professional Imaging for Epson. Epson’s SureColor F Series dye-sublimation printers comprise the F6200, F7200, and F9200.

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.

“For me, the difference will always be clarity because you’re always going to get a  cleaner, crisper print when you’re doing a print to paper and then transferring,” said Steven Moreno, founder and principal of L.A.’s MY Prints, a digital print shop that specializes in apparel prototyping and garments for entertainment industry costume houses, as well as flags, banners, and other display graphics. Most of MY Prints’ work is dye-sub-based. “For something with fine detail we would always want to use transfer paper.”

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.”

“Transfer is for a nearly endless array of applications—trade show graphics, high-end fashion, sports apparel, interior design, promotional products, interior signage, industrial and construction, retail and POP, etc.,” said Tommy Martin, Manager, Textile and Apparel Business Development for Mimaki USA. Last summer, Mimaki introduced the TS300P Production Dye Sublimation Printer. “Any polyester fabric or polymer-coated goods—ceramics, glass, slate, plastics, or metals—can be sublimated via a transfer method.”

Of course, you’re not going to be able to do everything using the exact same equipment.  “Most applications that aren’t flat need to be transferred with a contoured heat press that matches the shape of the item,” said Martin. “For example, a mug press or a mug wrap and oven for coffee mugs.”

Another advantage of the transfer process is that—counterintuitively, perhaps—it makes color management easier. In dye-sub printing, color profiles primarily focus on the transfer paper, not the final substrate. “You can switch fabrics around and it doesn’t have a huge bearing on the color accuracy,” said Check, “but changing the paper makes a big difference.” That said, part of the profiling process involves printing calibration targets onto the transfer sheet then sublimating the ink onto the target substrate. “Once that’s done, it helps build a profile for the paper.” The big variable in the color management and profiling process for dye-sub involves the print characteristics of the paper, in particular how much ink releases onto that paper.

That all said, are there any advantages to direct dye-sub printing? The number one benefit is the cost savings of not having to use a transfer paper. It’s hard to generalize given the variation in machines, substrates, etc., but the need to use specially coated polyester in direct printing doesn’t completely offset paper savings. Direct sublimation inks are about the same cost as transfer-based inks, but you are often putting down more ink when using direct disperse, so depending on what you’re printing it may be a wash cost-wise. But generally, there are can be cost savings.

“You could be eliminating as much as 50 cents to a dollar per linear yard in paper,” said Moreno. “If we’re going to do 300 yards, it adds up. If we’re not jeopardizing the clarity of the image, we can absolutely print directly to the fabric. The coating cost per square foot of fabric is less than the cost per square foot of paper.”

Beyond that, direct printing does have advantages for specific applications, especially soft signage, flags, and banners. The primary advantage of direct disperse for these applications is deep penetration of the ink into, and saturation of, the fabric. “When you print a big red flag, it basically has bleed-through,” said Check. “You’ll have that red on the front, and the images and text are in the correct orientation. The back side will also be red, and even if the text and images are reversed, someone can still see it and identify it. That’s a good thing for that application.”

“When we’re printing flags, we’ll definitely print right into the fabric,” said Moreno.

You do lose sharpness compared to transfer, but since signage and banners are viewed from a distance, so they may not need to be sharp. (This is related to issues of apparent resolution.)

Direct printing is also good for other applications, said Martin, such as “upholstery, stage backdrops, gaming tables, or where colorfastness and high UV resistance are required, and for applications that will need deep saturation of the ink.”

The advantages are not just image-related but also business-related. “You can build a business around just those applications [soft signage and banners] and that’s all you need to go after,” said Check. “You may not need versatility.”

Direct disperse also offers an advantage for apparel printing, also due to the deep penetration of the ink.

“When we’re going to print fabric stretches, there’s what we call a ‘smile’ that happens,” said Moreno. Most digital fabric printing starts with a white substrate. In a transfer method, where the ink sits close to the surface of the material, when the material stretches, it may be possible to see that white “smiling.” So direct printing, by virtue of the ink penetrating further into the material, can, shall we say, wipe off that smile.

Some users do have issues with direct printing on items meant to be worn. This doesn’t have to do with the printing per se, but rather with the coated polyesters you need to use. “The coating adds some stiffness, like a heavy starch,” said Check. “It adds some roughness or texture.” The feel or tactile characteristics of a fabric are referred to as “hand.”

Direct printing can also present problems with excess ink. “You’re laying down a lot of ink,” said Moreno, “more ink than will gas off into the fabric.” If you’re not careful, and don’t completely heat and dry the fabric, excess wet ink will pool on the surface, which can run if it gets wet, or smear and stain when rolled up and shipped. In the case of wearable garments like sports apparel, sweat can cause excess ink to run—or to have the colors run in the laundry. Unless you’re doing your own tie-dyeing, that’s generally not desirable.

One final advantage of a transfer process, especially for newbies to fabric printing, is that paper is a known quantity. “How to handle paper going through a printer is pretty straightforward,” said Check. “When you start putting fabrics through, fabrics can stretch and change shape. Transfer is easier to work with.”

“In my opinion, I would recommend starting off with transfer, because you’re not limited in what you can run,” said Moreno. “You open your doors to everything.”