Direct to Garment and Dye Sublimation
Our DTG and dye sublimation printing software can't parse transparencies that involve colour. Creating a colour by reducing its opacity to blend it with the empty space beneath it creates a design element that our software simply can't read.
The printing software we use can't parse gradients from colour transparent, so pixels that include any element of transparency. In simple terms, we can't print with a translucent ink; the software reads the colours and lays down the corresponding ink, but there's no corresponding ink for transparency! The results can be unexpected and usually won't match your expectations.
100% transparency is fine, so transparent backgrounds can be included in your artwork. Other than this, you're free to create artwork as you wish:
Gradients (colour to colour, not colour to transparency) can be used.
Complex or simple designs.
The inability to use gradients doesn't need to impact your designs though. For example, you can use textures or patterns to distress your designs if this is the effect you're going for.