Intaglio printing (āo bǎn yìn shuā) is a traditional printmaking technique where an image is incised into a metal plate — typically copper or zinc — and ink is forced into the recessed lines. When paper is pressed firmly onto the plate under high pressure, the ink transfers from the grooves to create a raised, tactile impression. The word breaks down literally: 凹 (āo) means 'concave' or 'sunken', referring to the engraved areas; 版 (bǎn) means 'plate' or 'printing block'; 印 (yìn) means 'to print'; and 刷 (shuā) means 'to brush' or 'to apply ink', emphasizing the inking process.

This method is widely used for high-security printing — such as banknotes, passports, and official stamps — because its fine detail and embossed texture are extremely difficult to counterfeit. It’s also valued in fine art printmaking for rich tonal gradations and expressive line work. While less common in everyday commercial printing today due to cost and complexity, 凹版印刷 remains essential where authenticity and durability matter most.