The Ink Passes on DTG Printing
Single-pass, multi-passes, four-passes and six-passes… These expressions are heard often in digital printing. Passes also make the difference between success and failure in direct-to-garment printing. Whether the garment will get a vivid, brilliant print – or whether the print will be barely visible and colourless. That’s why we would like to briefly discuss the ink passes in DTG printing in this article.
This article was also published in the German Magazine “TVP Magazin” – 03/2022 edition.
1 – What’s an Ink Pass?
In a typical DTG printer, a printhead moves back and forth along an axis, dispensing ink as it goes.
In simple terms, a pass defines how many times a printhead moves across the same spot, placing ink droplets in multiple layers at the same place. The final print result is the result of these many individual dots.
In addition to that, a printhead can print in both directions (bidirectional) or shoot in only one direction and return without applying ink (unidirectional).
2 – Single vs. Multi Pass
Single-pass means that an area is printed in a single pass. Multi-pass means that the same area is printed overlapping several times.
The numbers indicate the number of ink passes. In a four-pass print, the same spot was printed four times; in a six-pass print, it was printed six times.
The lower the number, the less often the printhead has to go over the same spot, and the faster the print.
3 – So would it be better to print everything single pass?
Unfortunately, no. Printing in single pass is faster, but it also has some disadvantages: First, it is much more prone to print defects, such as clogged nozzles, becoming immediately apparent.
As an example, a home renovation project can also illustrate this challenge. Let us say we want to repaint a wall with white paint. If the paint is applied only once in each area, irregularities or flaws will quickly become visible. All the streaks and lines are probably visible to the naked eye.
In the multi-pass process, mistakes are compensated for by overlapping the same area and painting over it several times. This reduces the risk of irregularities becoming immediately visible, such as the lines of a clogged nozzle.
In addition, most applications require more paint than can be applied in just one pass – this also applies to DTG.
For the same reason, if we want to whitewash a black wall, it will also be difficult to cover the wall with just one coat. Here, several coats are required.
4 – In part II of this article we will talk about:
- Multi-Passes.
- Pass optimisations in DTG
- Correct setting of colour passes
Read all about it n the next DTGMerch article!
5 – Fancy a Freebie?
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And as always, all the best, take care and be good!