Lines are scratched into the soft metal plate using any sharp instrument with the same freedom as a pencil. The effect is spontaneous, not formal. Cutting into the plate throws up, on each side of the cut, ridges of displaced metal, which are called burr. In the printing of the plate, these ridges will also take some ink and print a kind of inky glow around the line.
In all intaglio prints except mezzotint the design is produced from ink in lines or areas below the surface of the plate. The smooth surface is wiped of ink before printing, though some ink may purposely be left on the plate for tonal effects. Considerable pressure is used in the press to force the ink out of the lines and areas and, to an extent, to force the paper into them, so the final printed image will appear to be slightly raised above the surface of the uninked paper.