How does DTG printing work?

DTG printing works by applying inks directly to T-shirt fabrics, in contrast to methods that apply DTG inks indirectly using screens or paper. It does this by using a modified type of inkjet printer that can print water-based inks known as aqueous inks. To apply these inks, DTG printing uses a four-step process:

Prepare digital art files
Pretreat and cure the t-shirt
Print on the t-shirt
Cure the ink

Let's break down these steps:

1. Preparing digital art files

DTG printers apply inks using a pattern based on a digital file. DTG printing software works best with formats such as PSD and PNG that support transparent backgrounds, but it also accepts other common graphics file formats such as JPG and TFF.

Graphics design programs such as Photoshop that use these programs usually use color models based on red, green, and blue (RGB). In contrast, DTG printers use models based on cyan, magenta, yellow, and black (CMYB). To manage this format difference, DTG printing software uses Raster Imaging Processor (RIP) software to convert RGB files into CMYK files.

2. Pretreating and curing t-shirts

The type of ink used by DTG printers works best with natural fibers such as cotton, bamboo, and hemp. To ensure the ink displays correctly, DTG uses a pretreatment machine before printing a t-shirt. Pretreatment applies a liquid solution that keeps white ink from soaking into the shirt and discoloring it while also preventing it from smearing or mixing with colored inks.

After the pretreatment solution has been applied, it is cured with a heat press or air dryer to make the t-shirt printing surface flatter. Fibers such as cotton normally stick up. Curing flattens the fibers to provide a smoother surface for printing.

3. Printing on t-shirts

After pretreatment, t-shirts are readied for printing by placing them on a flat platform called a platen. The platen holds the t-shirt in place to keep it flat and aligned in the right spot for inks to be applied. T-shirts can be aligned correctly to platens by lining up their neck collar, shoulder seams, or side seams on shirts that have them. Once a t-shirt has been aligned on a paten, it can be printed by feeding the paten into the printer.

4. Curing ink

After a t-shirt has been printed, the ink must be cured to affix it to the garment properly and ensure durability through repeated washings. Curing may be done with a heat press or forced air dryer.