Underbase.

The white ink layer that sits between the colour and the garment, so the colors read as themselves instead of picking up the fabric underneath. On DTG it goes down first, straight onto a dark shirt. On DTF the order reverses: the printer lays the colour on the film first and the white over it, and there the white also works as the binder for the adhesive powder, so it does a structural job as well as an optical one. Its opacity and its registration with the layers above decide whether the print looks clean or muddy. Too thin and the colors go dull; too heavy and the print stiffens, which the customer feels before they look at it.