Wood engraving is a printmaking and letterpress printing technique, in which an artist works an image or matrix of images into a block of wood. Functionally a variety of woodcut, it uses relief printing, where the artist applies ink to the face of the block and prints using relatively low pressure. By contrast, ordinary engraving, like etching, uses a metal plate for the matrix, and is printed by the intaglio method, where the ink fills the valleys, the removed areas. As a result, wood engravings deteriorate less quickly than copper-plate engravings, and have a distinctive white-on-black character.
Thomas Bewick developed the wood engraving technique at the end of the 18th century. His work differed from earlier woodcuts in two key ways. First, rather than using woodcarving tools such as knives, Bewick used an engraver's burin (graver). With this, he could create thin delicate lines, often creating large dark areas in the composition. Second, wood engraving traditionally uses the wood's end grain—while the older technique used the softer side grain. The resulting increased hardness and durability facilitated more detailed images.
Wood-engraved blocks could be used on conventional printing presses, which were going through rapid mechanical improvements during the first quarter of the 19th century. The blocks were made the same height as, and composited alongside, movable type in page layouts—so printers could produce thousands of copies of illustrated pages with almost no deterioration. The combination of this new wood engraving method and mechanized printing drove a rapid expansion of illustrations in the 19th century. Further, advances in stereotype let wood-engravings be reproduced onto metal, where they could be mass-produced for sale to printers.
By the mid-19th century, many wood engravings rivaled copperplate engravings. Wood engraving was used to great effect by 19th-century artists such as Edward Calvert, and its heyday lasted until the early and mid-20th century when remarkable achievements were made by Eric Gill, Eric Ravilious and others. Though less used now, the technique is still prized in the early 21st century as a high-quality specialist technique of book illustration, and is promoted, for example, by the Society of Wood Engravers, who hold an annual exhibition in London and other British venues.