Digital decorating is an ideal solution for small runs and on-demand printing, as the setup and production is quick and simple.
To get a better understanding of the benefits of digital printing, we will take a look at two of the most popular forms used for apparel decoration: direct-to-garment (DTG) printing and dye sublimation (or sublimation, for short). Though similar in some aspects, they are quite different in others.
For the most part, a DTG printer uses a horizontally moving inkjet print head to apply an image directly onto the surface of a garment, which is mounted on a platen that gradually feeds the garment through the machine directly below the print head. Special, quick-drying inks designed specifically for the fabric being printed — typically 100% cotton — are used in the process.
Unlike screen printing, the ink colors are applied continuously in a single plane, rather than sequentially in layers. Though the inks dry when applied, they have to be cured through the use of some form of post-printing heat apparatus, such as a heat press or garment dryer.
In comparison, sublimation is a digital dye process used for printing graphic and photographic images into polymer and polyester surfaces. The inks used in the DTG process apply color to the top of the substrate’s surface, whereas sublimation dyes penetrate the surface to recolor from the inside out. Thus, the chemistry of the two processes is quite different, with sublimation relying on molecular bonding, while DTG relies on surface adhesion.
The sublimation process uses an inkjet printer equipped with sublimation dyes to print an image onto sublimation transfer paper. The printed transfer paper is then applied to the blank substrate using a heat press.
The combination of heat and pressure cause the sublimation ink to convert into a gas, which is received simultaneously by the substrate’s opened polymers. (This is an over-simplified explanation of the process, but it works for our purposes.) After the heat application is completed (about a minute), the transfer paper is removed and discarded. When the product cools down, the sublimation dye is encapsulated within the surface (instead of on top). The result is a high-resolution, permanent coloration that won’t peel or crack. And in the case of apparel, sublimation will not fade, even after multiple washings.
The limitation of sublimation is that it only works on polymer-based surfaces, which — in the case of apparel — means some form of polyester. But with the surging demand for polyester performance apparel, sublimation is the ideal process for the product.
Another key point with digital printing is that the inks and dyes will only bond with the surfaces for which they were created. DTG is primarily a cotton application, while sublimation is limited to polyester. Both will work on blended fabrics, but the colors may appear faded, muted or washed out.
With all digital printing, there is a challenge to deliver consistent color results on the final product. Both DTG and sublimation processes rely on digital artwork created with standard software programs such as CorelDRAW, or Adobe Photoshop and Illustrator. But it takes a further level of enhancement to properly deliver accurate color output at the print head.
DTG relies on raster image processor (RIP) programs that may not be included in the initial equipment purchase. Sublimation systems rely on custom printer drivers, color palettes and profiles that usually are provided by the manufacturer.
THE CHALLENGES IF A DESIGN REQUIRES WHITE INK ON A DARK GARMENT:
In reality, white ink is not needed on every job; thus, not all DTG printers offer it. But before you insist on having white ink in your promo project, make sure you balance your desire against your need. White ink does present challenges, one of which is the artwork that has to be prepared differently to accommodate white ink. So know what you are getting into, especially since it typically raises the price tag in addition to the level of production complexity.
What about white ink for sublimation? It’s not available. There are some alternative methods, such as allover sublimation where you apply an image that completely covers the surface of a shirt. You start with a white shirt and then recolor it while adding graphics all in one step (per side). It requires a wide-format printer and heat press, but is gaining in popularity for creating retail-inspired looks for a multitude of market niches.
Whereas DTG has the advantage over sublimation in terms of printing on colored surfaces, sublimation takes the cake when it comes to the range of products that can be decorated. Sublimation-ready merchandise includes plaques, awards, promotional products, photo panels, memorial products, signage, mugs, flip-flops, koozies, flags, tiles, iPhone covers, laptop sleeves, stadium seats, acrylics, pet products, etc. One machine can decorate hundreds of products!
WHAT DOES ALL THIS MEAN TO YOU AS A CONSUMER OR BUSINESS OWNER?
Not a whole lot unless money, small quantities and time are a big issue in your promotional product needs. If you can only afford to do small runs or quantities of a product, than you most certainly will have to look for a printing or promotional company that can do digital printing for such cases. (We can.) The drawbacks to digital printing vs screen printing or offset printing are that the inks used in digital printing tend to fade quicker over repeated washing when it comes to garments. So the color fades muck quicker.