Mezzotint on stone (ossa sepia, manière noire)
- arabic gum
- nitric acid
- lithographic ink
- rosin and talc
Mezzotint on stone – ossa sepia – is a beautiful lithographic negative technique. The drawing is similar to the traditional intaglio mezzotint on metal plates; you can do it (the scraping) using the same materials. The velvet black background is done when grinding the stone.
The edges of a well-grained and dried lithographic stone should be covered with gum arabic for protection against blackening.
The stone should be leveled and covered with asphalt diluted with turpentine. The layer should be even and uniform. A glass or other turpentine evaporation slowing material may be placed just above the surface of the stone.
* Asphalt can also be evenly rubbed with a cloth, preferably by applying several subsequent layers.
After a day’s wait start drawing using scrapers, needles, sandpaper and other tools to scrape the surface.
Afterwards the drawing should be cleaned (if turpentine is not enough, use petroleum), wiped with talc and etched.
Asphalt is very hard and acid-resistant, however, delicate tones obtained during scraping should not be etched too rapidly. But all the scraped surfaces should be etched with quite a strong etching solution.
After the etching substance is removed and the stone is dried, the drawing should be washed away with turpentine and, if this is not be possible, with a different non water-based solvent.
Next, rub the asphalt again, wet the stone with water and roll it up.
The second etching depends on the drawing.