The first thing to understand while printing with a D2 system is when and when not to use white ink. D2 inks are translucent and rely on the reflectiveness of the surface being printed on for correct tones and color vibrancy. The basic rule of thumb is if you need to keep the integrity of your color and the print is on a non-white fabric, then you will need to use white ink.
An example of this is if you are printing a black image on a red shirt. Black is dominant and will overpower the red, so no white ink would be needed. On the other hand, if you are printing green on red, the color of the shirt will affect the print and cause a brown image. To keep the integrity of the original color, you need to print a white ink underbase.
If you wanted to print on a white garment and needed your colors to be vibrant, you typically would not print white ink but instead, you would use a light garment pretreatment to enhance the color vibrancy and overall washability.
—ColDesi
