Line engraving is a term for engraved images printed on paper to be used as prints or illustrations. The term is mainly used in connection with 18th- or 19th-century commercial illustrations for magazines and books or reproductions of paintings. It is not a technical term in printmaking, and can cover a variety of techniques, giving similar results.

Steel engraving is an overlapping term, for images that in fact are often mainly in etching, mostly used for banknotes, illustrations for books, magazines and decorative prints, often reproductive, from about 1820 to the early 20th century, when the technique became less used. Copperplate engraving is another somewhat outdated term for engravings. With photography long established, engravings made today are nearly all artistic ones in printmaking, but the technique is not as common as it used to be; more than other printmaking techniques, engraving requires great skill and much practice, even for an experienced artist.

Engraving for the purpose of printmaking creates plates for intaglio printing. Intaglio engravings are made by carving into a plate of a hard substance such as copper, zinc, steel, or plastic. Afterward ink is rubbed into the carved areas and away from the flat surface. Moistened paper is placed over the plate and both are run through the rollers of an intaglio press. The pressure exerted by the press on the paper pushes it into the engraved lines and prints the image made by those lines. In an intaglio print, the engraved lines print black.

Wood engraving is a relief printing technique, with the images made by carving into fine-grained hardwood blocks. Ink is rolled onto the surface of the block, dry paper is placed on top of the block and it is printed either by rolling both through a press, or, by hand, using a baren to rub the ink from the surface of the block onto the paper. In a relief print, the engraved lines show white.

The art of engraving has been practiced from the earliest ages. The prehistoric Aztec hatchet given to Alexander von Humboldt in Mexico was just as truly engraved as a modern copper-plate which may convey a design by John Flaxman; the Aztec engraving may be less sophisticated than the European, but it is the same art form. Jewelry and many types of fine metal works frequently are engraved as well as furniture. Engraving often is used as an embellishment of knives, swords, guns, and rifles.

The important discovery which made line engraving one of the multiplying arts was the accidental discovery of how to print an incised line. This method was known for some time before its real utility was realized. The goldsmiths of Florence in the middle of the 15th century ornamented their works by means of engraving, after which they filled up the hollows produced by the burin with a black enamel-like substance made of silver, lead, and sulfur. The resulting design, called a niello, was much higher in contrast and thus, much more visible.

As this enamel was difficult to remove, goldsmiths developed alternate means of viewing their work while still in progress. They would take a sulfur cast of the work on a matrix of fine clay, and fill up the lines in the sulfur with lampblack, producing the desired high-contrast image.

It was discovered later that a proof could be taken on damped paper by filling the engraved lines with ink and wiping it off the surface of the plate. Pressure was then applied to push the paper into the hollowed lines and draw the ink out of them. This was the beginning of plate printing.