Intaglio was a very common method of image reproduction between 1500 & 1900 and the resulting images were incredibly precise.
It’s quite simple;
- Cut into a hard surface (such as a copper plate)
- Cover it in ink, wipe off the excess.
- Press paper or fabric onto the surface, remove it and the image will have been transferred. Force from pressing causes ink to transfer from the grooves of the engraving onto the print medium.
Bank notes have illustrations which were originally copper plate engravings (intaglio).
Woodblock prints are in relief. Relief printing was an alternate and common method where ink is applied to the surface details of an engraving but not to the grooves or recesses. The image is transferred by pressing paper or fabric onto the engraving. Or in the case of a stamp, the engraving is placed onto ink, then onto paper - transferring the image.
You make relief prints at home with your shoes when you track mud from outside, creating foot prints.
Relief printing is more primitive in that it requires less force to transfer the image than intaglio and can be reproduced by hand. Intaglio printing commonly involved a heavy rolling press to industrialize image reproduction, retain incredible detail and image integrity.