Direct to garment printing (DTG) is printing on textiles using inkjet technology which usually utilizes specialized water-based inks. Most systems are CMYK however there are exceptions like the Kornit DTG Hexachrome system. DTG is particularly effective for short runs, full color printing, or for reproducing fine detail.
STEP 1: PREPARING THE GARMENT
DTG usually requires a pre-treatment solution to be applied to the garment before the ink can be printed on it. This solution is a “primer” that is designed to create a bond between the ink and the garment. All dark colored garments require this process but it is optional on light colored garments. Depending on the equipment, the pre-treatment may be applied by the DTG printer or it may have to be applied beforehand in a separate process.
STEP 2: PRINTING
The shirt is placed on a platen that keeps it flat and smooth during printing. It is essential that the shirt is flat as possible or the print heads will move away from the substrate and the printing can become blurry. The artwork is loaded into specialised RIP software (rasterized) and is sent to the printer. For light garments the machine makes a pass over the garment surface, while applying a highly controlled spray of each of the process inks. This may be one or multiple passes. For dark garments it first lays down a white underbase and then returns to print the process inks.
STEP 3: CURING
Once the image is printed on the shirt, the ink needs to be cured in order to make the image permanent. This heat may be applied in a conveyor oven (dryer), a special drawer-based cabinet oven (dryer), or using a heat press. The length of time and amount of heat are dependent on the exact ink system, and the thickness of the ink. As with all types of inks on all garments/fabrics the atmospheric conditions or the temperature or humidity in the garment may also affect the cure.
- DTG is less complicated than traditional screen printing. Compared to screenprinting, DTG requires less experience and specialised knowledge, it is simpler with many less steps, it uses fewer chemicals, and it takes up less floor space.
- 100% Ring Spun cotton fabrics garments are the easiest substrate for good results with DTG since they have a smooth print surface. Many blended fabrics also work but they can be more difficult. 100% polyester previously was not able to be printed DTG but now advanced equipment and ink sets are available which get superior results, even on polyester.
- DTG is a great solution for print-on-demand, on-line stores, and for individual special projects. It allows for single pieces or short runs to be affordable or when there is particularly fine detail.
- A high resolution is best for artwork. 300 dpi at full size is the minimum resolution for the best results. Artwork with an inferior resolution will not give ideal results but with DTG you may get passable results that are superior to screenprinting from such files.
- For the highest level of quality always pre-test the exact garment you are going to print. Different garments in terms of color, fabric, and means of manufacture require different DTG printing parameters. Garments of the same color and style but from even a different factory (for example a different country of origin) may require different printing parameters and therefore should be retested.
- Heat pressing the garment before printing can give superior results as a nice flat surface is the best printing surface.
- The Gildan® 63000, 63v00, 63V00L, 76000, 76000B and 76000L get superior DTG results due to the 100% ring spun cotton, consistency of manufacture, and the tight knit of the fabric. Halftone dots reproduce better and you also get a nice even print on broad areas of color with the smooth fabric of Gildan Softstyle® & Premium Cotton shirts.