By Melissa Donovan
Part 1 of 2
Direct to garment (DTG) printers are an ideal alternative to screenprinting. For smaller runs or orders of one, these digital devices are economical. The ink sets that accompany them are designed with this in mind. Not only do they offer high-quality prints, but are available in cost-effective volumes depending on the user’s needs.
Most of these inks are water-based pigments and available in cartridges ranging 220 to 600ml. To keep pace with busy print shops, many devices are equipped with feature sets to alert the user when ink needs to be refilled or is running low. Of note are white inks, which continue to gain popularity as more people are attracted to printing on dark shirts.
Water, Water Everywhere
Water-based pigment ink is the consumable of choice for DTG printers. It absorbs well into fabric, works with the technology—printheads—under the hood, and is comfortable and safe to wear.
Differing from sublimation—when ink is heated to a gaseous state and infused into the material—the DTG process involves water-based ink laid on top of the garment and then fused with the fabric using a heat press. While the ink does penetrate into the fibers slightly, it isn’t as deeply infused as sublimation.
Formulated for fabric, water-based pigment ink is used, according to Jerry Smith, DTG trainer and technician, MESA Supplies, because other inks cause issues with separation, settling, and clogging.
“Almost all DTG printers use water-based inks and piezoelectric printheads because DTG inks need to have binders in the ink that will allow it to adhere to the garment or fabric being printed on. The binders are heat activated. So a piezo printhead, which uses electric pulses to jet the ink out of the printhead, is preferred over a thermal printhead,” explains Mark Bagley, director of marketing, Brother International Corporation.
Most DTG printed pieces end up being worn by the buyer. With minimal potential for harsh chemicals, water-based pigment ink is safe for human touch. “The more natural content of the ink makes it very safe to wear and also be in contact with skin,” says Paul Green, product manager, OmniPrint International.
Peter Choi, president, All American Manufacturing & Supply, also points out that it provides a soft hand over other inks like plastisol based.
For a printer with a small footprint, the size of the ink cartridge is important. Most cartridges used in DTG printers run anywhere from 220 to 600ml on average. And cartridges aren’t the only option, bulk ink systems are an alternative. Which to use depends on the configuration of the printing device.
“It depends on the size of the printer, the throughput, and the shelf life of the ink. Small printers can work with 150ml bottles, but industrial printers that have a higher throughput and are expected to work long hours need to have larger bottles of up to four liters in order to work without the interference of replacing bottles,” shares Orit Raz, product marketing manager, ink consumables, Kornit Digital.
For example, MESA’s Summit XT DTG printer holds a total of six cartridges and each is one-inch thick by four inches tall and 11 inches deep. Five inches of the depth protrudes from the front of the printer to keep its overall size down and to make refilling the cartridges less complicated. The exposed part of the cartridges also make it easy to gauge the level of ink, according to Smith.
Epson’s SureColor F2000 uses six 600ml ink cartridges that are located inside the printer and are accessible through doors located on the front of the device. “By arranging the cartridges in this way, it greatly reduces the space requirement of the printer,” shares Matthew Rhome, business development, fabric imaging, Epson.
Cartridges aren’t the only option, there are also bulk systems, explains Green. “With bulk ink you are simply filling a bottle on the printer. The ink is sold in 250ml, 500ml, and one liter bottles. Because you are buying the ink straight from the bottle and in higher amounts the price is cheaper with no extra cost of the cartridge itself. Bulk ink systems are also quite compact and help keep a small footprint.”
With any printing device, monitoring ink levels is essential for production. DTG printers are no different. Ink should refilled often based on estimated volume. Certain printers include technology to gauge when ink should be changed out.
Paul Crocker, marketing director, AnaJet, Inc., cautions that ink cartridges should never run completely empty on a DTG printer. The company manufactures its cartridges intentionally with more ink than stated to avoid complications resulting from unwanted air being introduced into the lines with empty cartridges, as air in the lines can cause the printheads to dry out and clog.
“How often you have to refill your ink depends on the size of your printers and the number of prints. Most customers tell me that they refill monthly. I recommend refilling when your cartridges are about ¾ depleted,” shares Smith.
Choi agrees that it depends on the printer and number of prints. He gives the example that if you use a liter of white ink, you can print about 250 shirts on average per liter. Per a liter of CMYK, you could print about an average of 1,000 shirts.
For tools that help alert the user when ink is low, Raz points to sensors that indicate ink is out or about to be finished.
The Epson SureColor F2000 features a visual indicator on the printer’s graphic display that informs the operator of the level of ink remaining in the ink cartridges. It also displays a warning message when ink is low or when an ink cartridge is empty.
Mutoh America, Inc.’s ValueJet 405GT printer uses “smart” cartridges, according to Randy Anderson, product marketing manager, Mutoh, which allows the monitoring of ink usage and will signal an alarm when ink is low or has run out.
“A few cartridge-based systems will give you ink levels showing what is left in each cartridge. With bulk ink bottles you can see the level in the bottle visually when printing,” suggests Green.
New formulations of white ink and reworking of circulation systems have contributed to an increase in white ink usage. More users are printing to dark or colored shirts, expanding output potential indefinitely.
“White inks contain titanium dioxide because it has so far been the only reliable method to make the ink print as a true white, but titanium dioxide is heavy and tends to settle and cause clogging fairly quickly,” explains Smith.
Most printers include recirculation systems to control white ink clogging. For example, a White Ink Control System is found on MESA Supplies’ Summit XT DTG printer to prevent settling and clogging of white ink.
Epson’s UltraChrome DG new white ink formula reduces sedimentation, clogging, and delivers high-density white colors on fabric.
“Improvements like printhead ‘wet clapping’ has allowed for white ink up to 30 days with no clogging issues. Now that people feel less challenged about using white ink for DTG the floodgates have opened to darker color garments. With the amount of vibrancy you can get out of a color shirt with white ink, I don’t see a plain white tee ever taking over,” shares Green.
Bagley says “the popularity of white ink is actually dictated by the customers who the garments are going to be printed for. There are some target markets that will absolutely require a dark colored garment to be used. If this is the case, then white ink is extremely popular and the customer will be willing to pay the additional cost associated with printing white ink.”
According to Crocker, most businesses tell AnaJet that 80 percent of their customers want prints on dark shirts rather than just white.
“White ink is very popular as approximately 60 to 70 percent of business is on colored and dark shirts,” cites Taylor Landesman, digital sales, Lawson Screen & Digital Products, Inc.
Water-based pigment inks are the preferred choice for DTG printers. Not only do they absorb well into the fabric, they are ideal for the printhead technology found in these devices and feature a soft hand. Most of these inks are available in a number of cartridge sizes, with some options in bottles or bags in bulk. Depending on the printer and quantity of prints run on a regular basis, refills should happen frequently. White ink is a buzz in this segment of the industry, as advancements in consumables’ formulation and how the printers prevent clogging due to recirculation techniques create a much easier process for the end user.
The second part of our series on inks for DTG printers looks at ink options for specific devices.
Jul2016, Digital Output DODTG1607