One of the newest types of printing on the scene is Direct to Garment printing. This type of printing utilizes a very similar print engine to an ink jet printer you would find in your home except its a lot larger and prints water based inks you would find in silk screening.
First, if the image being printed has white ink or the shirt being printed on is a darker color which will require a white underbase (this allows for the brighter colors in the image to keep their vibrancy by printing on a white surface rather than the dark shirt) then the shirt will be sprayed with a liquid call pretreatment. This basically allows the white ink to lay on top of the fabric rather than fall through the fibers of the shirt since white ink is very thin. It also helps to gel/cure the white ink so that when the printer goes to print the layer of CMYK on top of the white the colors don’t mix together since the white is already partially dried/hardened. The next step is to flatten the fibers of the shirt by putting it under a heat press. This not only flattens the fibers but also cures the wet pretreatment fluid that was sprayed on the shirt.
First, the shirts are loaded onto a conveyor type system which is run by a linear actuator that carries the shirt under the print heads which disperse the ink. The movement of the shirt is similar to a piece of paper running through a inkjet printer. The ink is delivered directly on top of the shirt as the printheads go back and forth shooting out ink in a calculated quantity programmed by the printer software. The print process has 2 steps as described previously. These are the first pass of the shirt lays down any white ink in the image or any areas where white ink is an underbase to a brighter color. The next pass is just the CMYK color array and any additional white for more opaque areas.
Once the print is done, it is then transported to the curing mechanism. This can be either a conveyor dryer with forced air or a heat press. Here at Chesapeake Tees we prefer heat presses as it ensure the correct temperature is applied to all areas of the print. Forced air dryers work well but given there is no pressure or direct contact to the shirt the error rate may be higher. We also like the idea the ink is being pushed into the shirt fibers to help with washability. Curing with a heat press does require some precision. This includes exact pressure, temperature , and a medium (typically, silicon parchment paper) to ensure ink is transferred to the heat press.
So as you can see Direct to Garment printing is a really cool printing process and offers some really cool options which typical screen printing may fail to deliver. This includes easy and quick one off prints and a larger color gamut of printing. Overall, we are really big fans of DTG here at Chesapeake Tees, so if you are interested in having an order printed like this give us a ring!