Water-based ink.

This is the screen-printing sense. When a digital spec says water-based, as Printful does for its All-Over Cotton, it means pigment ink fired from an inkjet head, covered under pigment ink, and the mesh problem below does not arise. Water-based screen ink suspends pigment and a binder in water, so the print penetrates the fibers rather than sitting on top of them the way plastisol does. The soft hand comes from that penetration, and so does the main operating headache: the carrier evaporates, so the ink begins drying in the mesh the moment the press stops. Plastisol has no solvent to lose and will sit in a screen for hours without hardening. Water-based will block a fine mesh in minutes, and every block costs a wash-out, a re-registration, and whatever garments went through half-printed before anyone caught it.