The Direct-to-Garment (DTG) printing process is much simpler than many other decoration processes. Most of the work involved in DTG printing comes from the setup process. Pretreating the shirts and preparing the artwork are the most complicated parts of the DTG process. Once the shirt and the artwork are ready to print, the process is fairly simple. Read our article on Pretreating for DTG Printing for more information on that process. Every design that you will print with your DTG printer will have different variables that need to be accounted for, and so will each different type of garment. Be sure to test unfamiliar garments before printing, and it is also a good idea to perform a test print of new artwork as well.
Preparing the artwork for DTG printing primarily revolves around determining how much white and color ink will be necessary to print the design. Like pre-treat, the amount of ink needed to print the design is determined based on the weight and color of the garment being printed. The white underbase ink layer acts as the primer for the CMYK colors. In many ways it is very similar to painting a wall, when it comes to laying down a solid base coat in order for the paint to cover the wall properly. The CMYK settings revolve around setting the contrast, saturation, and amount of print coats that are necessary to print the design. Sometimes color may need to be printed twice to achieve the desired look. However, sending color multiple times will produce darker colors. So, if only one color needs an extra layer of ink, then delete the other colors first before sending the artwork to the printer again.
First the print operator must make sure that the platens on the DTG printer are clear of any fibers, fuzz, or other debris. Any debris under the garment could lead to ink being dragged or printed in an area where there should be no ink. Also, there are several different platens now, from standard 14x16 to youth to shoes, even. So be sure to familiarize yourself with the use of whatever platens you will need. Once the platen has been cleared, garment is threaded onto it if possible. It is very important that garments are threaded onto the platen. If the printer simply lays the entire garment on top of the platen, then the print surface is less stable and the ink can bleed through the front of the garment and onto the back.
With the garment on the platen, it is time to align it. This step is critical because once printing begins, there is no way to reclaim the garment if it is ruined due to design placement. The print surface should be lined up properly and fully covered in pretreat. Often, platens will have grids printed on them to help with the alignment process. With the garment in place on the platen, it is time to send the artwork to the printer. Once the artwork has been sent, initiate the print.
The printer will first lay down a base coat of white ink. Then, a second coat of highlight white is laid down. The amount of white necessary to print the artwork is determined by the type of product and color being printed. The printer will then lay down color (unless printing on a white shirt, in which case only color needs to be printed). Before removing the garment from the printer the print operator will double check the print quality and make adjustments if needed. Once satisfied with the print quality, the print operator will carefully remove the garment from the platen. The ink does not dry on its own. So, if the shirt curls or puckers up when removing the garment, then it can stain parts of it outside the print area permanently.
DTG printed garments are typically cured using either a conveyor dryer or a heat press. Conveyor dryers used to cured DTG ink are not like most screen print dryers. They require air to flow through the heating chamber so that the water-based ink is completely absorbed into the fabric. A heat press is a better solution for smaller shops for a few reasons. A conveyor dryer takes up a lot of space, are expensive to power, take much longer to cure the garment, and only serve the purpose of curing DTG prints. A heat press can cure the garment much quicker since it uses pressure unlike a conveyor dryer, costs much less, and is already a necessary piece of equipment for curing the pretreat.
A DTG print is cured using a heat press by threading the garment onto the platen if possible. The garment should sit under the heating element of the press to allow the design to be flash-dried for a few seconds, so that the ink is dry to the touch before being pressed. Most garments are then covered with parchment paper (to prevent ink from contacting the heating element) and cured at around 350 degrees for approximately 30 seconds. However, those numbers can differ based on the manufacturer of the ink. Once cured, the garment is finished and ready for sale! It is highly recommended to include wash care instructions with DTG products to ensure the print maintains the highest possible quality (washed in cold water, inside out).
Taking good care of your DTG printer is essential to maintaining consistent quality. There are likely both daily and weekly maintenance procedures that must be performed in order to ensure that your DTG printer prints beautifully every time, and that it does not break down. In the event that your printer does break down it is crucial to have a local contact that can repair, or at least diagnose, the issue. Finally, DTG printers work best when they are frequently in-use. Most DTG printers can run day and night, and actually use little power. Letting a DTG printer sit for an extended period can lead to a whole host of complications, so do your best to avoid long periods of stagnation between prints. If you have to go for a while between prints, then at least fire up your printer every week or two to perform a few test prints.
