Scraperboard

Sometimes referred to as scraperboard (especially in Great Britain), but usually called scratchboard in North America and Australia, is a form of direct engraving where the artist scratches off dark ink to reveal a white or colored layer beneath. Scratchboard refers to both a fine-art medium, and an illustrative technique using sharp knives and tools for engraving into a thin layer of white China clay that is coated with dark, often black India ink. There is also foil paper covered with black ink that, when scratched, exposes the shiny surface beneath. Scratchboard can be used to yield highly detailed, precise and evenly textured artwork. Works can be left black and white, or colored.

Modern scraperboard originated in the 19th century in Britain and France. As printing methods developed, scraperboard became a popular medium for reproduction because it replaced wood, metal and linoleum engraving. It allowed for a fine line appearance that could be photographically reduced for reproduction without losing quality. It was most effective and expeditious for use in single-color book and newspaper printing. From the 1930s to 1950s, it was one of the preferred techniques for medical, scientific and product illustration. During that time period, Virgil Finlay made very detailed illustrations, often combining scraperboard methods with traditional pen & ink techniques, and producing highly detailed artworks. In more recent years, it has made a comeback as an appealing medium for editorial illustrators of magazines, ads, graphic novels, and one of a kind pieces of fine art displayed in galleries and museums internationally.

Unlike many drawing mediums, where the artist adds in the mid-tones and shadows, with scratchboard the artist is working by adding in the highlights. The artist can use a variety of tools to scratch away the black ink from the board and reveal more or less of the white clay that is underneath (see materials list below for tools). After black ink has been removed as desired the work may be considered complete, or subsequently be colored with watercolors, airbrush, ink, color pencil or acrylics. Transparent mediums are generally used to color scratchboard, as they fill in the white scratches without affecting the black ink left on the board. After an area has been colored it can be scratched again, revealing more of the white clay. Sometimes the artist will color and scratch several times to create subtle shading or color variations. This technique can yield a graphic image that can be very detailed. Artists that begin with a white clay-coated board will add their own ink to the surface, and then scratch away the ink in the same manner as described above. After completion, the artwork may be varnished to protect it against damage.

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Wikipedia