intaglio

As a verb intaglio

is .

As a noun siderography is

a 19th-century process of reproducing steel-engraved designs for printing the design is engraved on a steel block, then hardened and used to transfer a raised-image version to a steel roller under heavy pressure the roller is then hardened and used as a die to impress duplicate images on printing plates for transferring to paper by the intaglio method.

As nouns the difference between intaglio and hardstone

is that intaglio is a design or piece of art which is engraved or etched into something while hardstone is precious stone or semi-precious stone used to make intaglio, mosaics etc.