High-drop printing means the printer can maintain precise ink ejection on surfaces with large height differences (e.g., over 3mm) without ink splatter, blurring, or head strikes. The print head’s ejection force, droplet velocity, negative pressure control, and standoff distance (nozzle-to-material gap) are key factors. Ordinary print heads have short firing range; when the standoff exceeds 2mm, they tend to produce scattered dots or trailing tails. Industrial heads designed for high-drop applications, such as Ricoh GH2220 and Kyocera KJ4B, offer higher droplet initial velocity and stable air-path control, allowing standoff distances of 5mm to 10mm or more. Additionally, auto-lift mechanisms and vision positioning systems rely on feedback from the print head. Therefore, without a suitable print head, reliable high-drop UV printing cannot be achieved.