What is DTG printing (direct to garment)
DTG, or direct digital printing on fabric: how pre-treatment, printing and curing work, and which curing method to choose.
DTG (direct to garment) is direct digital printing on fabric, most often used to decorate finished garments.
DTG is mostly used on cotton, but other fabrics such as linen, bamboo or hemp can be printed too.
It uses environmentally friendly water-based inks, which bond very well with the fabric once cured with heat.
The DTG printing process
DTG printing takes three steps:
pre-treatment;
printing;
curing the print.
Pre-treatment
Before printing, the fabric is treated with a special pre-treatment liquid sprayed onto the print area. It can be sprayed with a hand gun or with a dedicated automatic machine. The liquid is set into the fabric with a heat press.
Spraying with a hand gun
A hand gun takes some skill, because the pre-treatment liquid has to be sprayed evenly over the whole print area. Too much or too little can change the wash fastness and the print quality. Spraying should be done in a ventilated, enclosed area, and not next to the printer.
Spraying with a pre-treatment machine
A garment pre-treatment machine can stand next to the printer, because the process takes place inside a closed housing. Automatic pre-treatment machines give a fast, even and high-quality result every time. The amount of liquid and the area it covers are easy to change in the machine’s settings, for the best possible print quality.
DTG printing
The DTG, or direct digital printing, step itself is very simple: the garment is placed on a special platen, the file is opened in the printer software and the Print button is pressed. When printing from PNG files, the software works out where the white ink goes and how much: the printer first lays a white base where it is needed and then prints the colour image on top.
When printing is finished, the garment is taken off the printer and placed in one of the curing machines.
Curing DTG prints
To make the print durable, it is cured with heat after printing.
Heat press
A heat press is needed for pre-treatment anyway, so this is the cheapest option of all. The shirt is pressed in the heat press for 1–2 minutes at a temperature of 60 degrees. Although a heat press can be used, and most people do, we recommend one of the other curing methods for a better result.
Curing cabinet
We recommend a curing cabinet if only one printer is used. Unlike a heat press, a curing cabinet fixes the print with hot air without contact with any other surface. That gives a better final result and reduces the number of rejects.
Curing tunnel
A curing tunnel works much like a curing cabinet, but because it uses more electricity we recommend it when several printers are printing at the same time.
Equipment and supplies
Printers, heat presses and supplies for textile printing are under DTF and textile printing, and video tutorials are in the Print School.
