Plastisol is a PVC-based ink that stays wet on the screen and needs heat to cure. It sits mainly on top of the fabric, giving bright, opaque colour and sharp detail, but a thicker print can feel heavier and less breathable. Water-based inks use water as the main carrier and penetrate the fibres. They give a softer hand feel and a more washed-in look, which suits vintage and lightweight tees.

Colour on dark tees

Water-based inks are naturally more transparent, so bright colours on dark tees are harder. Printers may use an underbase, more opaque water-based formulations or discharge ink, which removes dye from suitable cotton fabrics before adding colour. Discharge results depend on how the fabric was dyed, so test on your actual tee colours. Plastisol covers dark fabrics more easily.

Curing

Both ink types need correct curing. Plastisol must reach its cure temperature through the whole ink layer. Water-based ink must have the water driven out and reach its cure conditions, which can take longer. Under-cured prints of either type may crack, fade or wash off. Ask the printer how cure is checked in bulk.

Fabric matters

Water-based inks work best on cotton and cotton-rich fabrics. On polyester-rich blends, dye migration and adhesion can be issues for both inks, so low-bleed products may be needed. Ask the printer to sample on the exact fabric and colour.

Testing

Wash printed samples with a named procedure such as ISO 6330 at your care label settings and inspect for cracking, fading and peeling. Check colour fastness to washing with ISO 105-C06 and to rubbing with ISO 105-X12, since some prints can rub off onto other items.

What to specify

Write the ink type, mesh or deposit if agreed, underbase or discharge use, the approved strike-off and the washed sample in the print spec. Agree that bulk prints are compared with the washed reference.

If you change ink type for an existing design, approve a new strike-off rather than assuming the colours will match.

Also confirm what each printer needs for production, such as artwork files, colour references and the number of screens, since these affect set-up costs and minimums as much as the ink choice itself.