What is high-drop UV printing? Simply put, it means printing patterns on uneven, bumpy, or even curved surfaces — such as shoes, masks, or cylindrical objects. Anything that is irregularly shaped with an uneven surface basically falls into the category of high-drop printing. This type of printing is also called high-elevation printing. It's important to note that not all printheads can handle high-drop printing. A standard UV printhead typically cannot exceed a drop height of more than 3mm.
High-drop printing is necessary when the product surface is uneven or has contours, so the printhead must be raised — the distance from the highest to the lowest point of the printhead is generally more than 3mm. Currently, printheads commonly used for high-drop printing include the Ricoh G6, Ricoh G5i, and Toshiba models. The main characteristics of these printheads are strong jetting force and high firing frequency. Even after being raised, they can still eject ink using high voltage and automatically adjust droplet size. This ensures that the printed pattern does not suffer from ink deviation or misting, and the colors remain accurate, landing precisely on uneven surfaces.
However, even with high-drop printheads, it is generally recommended to keep the drop height within 20mm for optimal results. To achieve good high-drop printing, a suitable printhead alone is not enough — the UV printer's control board must also support high-drop mode. It is also best to use specialized high-drop ink.
That said, high-drop printing has its drawbacks. First, the printing speed is significantly slower, often limited to unidirectional printing. Second, it places greater strain on the printhead, shortening its lifespan. For example, a printhead used for standard flatbed printing might last 2–3 years, but with frequent high-drop printing, the printhead may start showing issues after about a year.