Sublimation ink is a particular type of ink that can be used to print on various materials, including cardstock. Sublimation ink doesn't rely on heat to transfer the ink onto the paper, unlike traditional printing methods. Instead, it uses a special dye that turns into a gas when heated. This allows the ink to be transferred directly onto the cardstock, resulting in a high-quality, full-color print. As long as you have a compatible printer and cardstock, you can use sublimation ink to print your own custom cards.