Discharge Printing

Discharge printing doesn't add a layer of ink on top of a dark shirt so much as strip the shirt's own reactive dye out of the fibers and replace it with pigment in the same pass. A discharge agent in the ink paste breaks down the dye during curing at around 320°F, and the fabric comes out of the dryer bleached in the printed areas before the new pigment color sets into that same spot.

The result is a print buyers can't feel — run a hand across a discharge-printed black tee and the design doesn't read as a separate layer the way a heavy plastisol print does. This is the look behind a lot of vintage-style band and brewery merch on 100% cotton shirts like a Bella+Canvas 3001, where the whole point is a shirt that already feels broken-in on day one.

Discharge only works reliably on fiber-reactive-dyed, high-cotton garments — poly-blends and some fabric dyes resist the agent entirely, so a shop needs to know the exact garment and dye lot before quoting it, and results can vary slightly between lots of the 'same' shirt color. Light colors printed over a discharged base often come out with a faded, slightly heathered look rather than a flat, saturated one.

A frequent misunderstanding is expecting discharge ink to match a Pantone swatch exactly the way plastisol does. Because the final color depends partly on how completely the garment's own dye discharges, the same ink formula can shift subtly shirt to shirt or dye lot to dye lot — a trade-off buyers accept for the hand feel, not a defect in the print.