Desktop Digital Transfers

A constant contributor to both industry events and trade publications, Jimmy Lamb is also the manager of communication at Sawgrass Technologies. Learn more about Sawgrass Technologies at http://www.sawgrassink.com.

Regardless of the size of the operation, it’s wise for garment-decorating businesses to have a simple method for creating printed samples of products to deliver to clients. In almost every sales situation, the client will expect a “proof” of what the final product will look like before they sign-off on the job.

With embroidery, it’s relatively simple to just put a shirt or cap on a machine and sew the logo. But screen printing poses challenges, as it doesn’t make sense economically to create a single item due to the setup costs.

But sampling isn’t limited to product proofs. In reality, one of the best sales techniques a decorator can use is to present the potential client with a finished product that includes their logo. In the promotional-products world, this is referred to as a spec sample. (In my world it’s referred to as a moneymaking sales tool.)

So how can you economically create high-quality samples? Regardless of whether you need product proofs or sales samples, desktop printing using digital transfers is the key. With a ballpark range of $500 to $2,100 (not including a heat press), startup costs are quite reasonable. But one of the most appealing aspects of digital transfers is the capability of “on demand” printing, which is why it’s so ideal for proofs and samples.

Technology review

Modern digital heat transfers rely on specialty inks, not on adhesives. Images are printed with an inkjet printer (using the proper type of digital ink) onto commercial transfer paper. The paper is placed face-down on the product and heat is applied with a press. The combination of heat and pressure causes the ink to transfer from the paper onto the product. The transfer paper is then removed and discarded, leaving behind a vivid, full color print on the surface of the item that was decorated. (In the case of sublimation, the image is actually embedded in the surface.) Depending on the equipment, print and press time (combined) is under two minutes.

Digital desktop printing does not require color separations, screen creation, station setup, etc. Provided the artwork is of good quality (ideally about 350 dpi at the output size), transfers can be printed within minutes.

It’s important to use the proper ink for the surface being decorated. It’s a matter of chemistry and bonding. The wrong choice will yield inferior results in the long run—the quality and longevity of the image will suffer.

For example, cotton shirts require inks designed to bond to cotton fibers. But polyester or polymer fibers, on the other hand, necessitate sublimation inks. (Both types of inks typically work on blends, but the colors may be muted.) Sublimation uses the same production process as any other digital transfer. The real difference is in the chemical process.

Sublimation is actually a dye specifically formulated for polymer fibers. During the heat press phase of production (400°F), two important things happen: the sublimation ink turns into a gas and the polymer fibers of the item being decorated open up. The sublimation ink then permeates the fibers (as opposed to adhering to their surface). When the heat is removed the fibers close back up and permanently retain the sublimation dye. The end result is that, with garments, the image will not fade, crack or peel with multiple laundering.

In the case of hard substrates, the surface will not chip, scratch or peel. There are many substrates available for sublimation, including those popular trucker’s style caps, plaques, awards, photo panels, spirit items, promotional products, signage, flags, flip-flops, home décor, jewelry and many more.

Notes on color

Regardless of which ink set is in use, one of the challenges of desktop digital decoration is color management. With screen printing and embroidery, it’s easy to visually see what the real color of the inks and threads. But with desktop digital printing, you are actually creating the colors via your software, then, the printer mixes various base colors together to deliver the final image.

The first problem is that the colors coming out of the printer don’t always match what’s on the computer screen. There are two basic reasons for this: color gamut and color conversion.
Color gamut refers to the range of the color spectrum that a device can reproduce. In the case of a computer monitor, the range of color is typically larger than that of an inkjet printer. Thus, it’s possible to have colors on the screen that cannot be exactly reproduced by a printer.

The second aspect is that monitors typically use an additive process (RGB) to create color, whereas a digital printer uses a subtractive process (CMYK) to create color. Thus, you are encountering a translation issue when it comes to the exact recipe of reproducing color from screen to printer.

The key to solving this common challenge is to work with specific color profiles that have been designed to create the best match between a range of specific input and output colors. Most manufacturers of digital transfer systems offer pre-defined color palettes and or software modules to deal with this.

Color management can get even more challenging when trying to match a digital color to a screen print color, and this is especially problematic in terms of producing spec samples. Perhaps the best way to tackle this issue is to print out a specific color chart, then apply it to the desired product using the transfer process. This will show the full range of specific digital colors as the look on a finished product and can be used as a visual reference for matching up to the screen printing inks. Then, start creating a cross-reference chart to assist with matching digital samples to screen-printing production.

Most color profile systems allow for the creation of spot colors that can be saved. In the long run, you should able to create a decent database of defined colors. However, it should be noted that, because of the physical difference in the inks (and the process) it may not be possible to get an exact match.

While there are certainly limitations to the process, all things considered, digital transfers are versatile and profitable and they certainly can hold their own against more traditional decoration processes for creating spec samples.