Ivan Shishkin, Cliff (1878). The State Tretyakov Gallery, Moscow
Using styluses (steel needles of different diameters), the engraver scratches the drawing on the primer, exposing the metal underneath. The reverse side of the board is varnished and then immersed in acid (in some cases, it is showered with acid). It gnaws metal in exposed areas, creating depressions for ink to enter later. The depth and width of these grooves depend on the concentration of the solution and the duration of the acid exposure — the more concentrated is the liquid and the longer the plate is in it, the wider and deeper the depressions will be, and, accordingly, the darker will be the lines on the print.
Afterwards, ink is distributed over the surface of the board using a cloth swab or a cardboard blade, and the excess is removed with the same material. The plate is additionally cleaned with a tarlatan rag (hard starched gauze or muslin). The board is placed on the press with the pattern facing up, covered with damp paper and a piece of cloth or felt. Pressing on them, the machine shaft squeezes the ink from the plate onto the paper.
Interesting facts about etching. The great innovator Rembrandt often resorted to etching in his work. He masterly used this technique, which is testified by the history of the Six’s Bridge