Engraving is the practice of incising a esign onto a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing images on paper, which are called engravings. Engraving was a historically important method of producing images on paper, both in artistic printmaking, and also for commercial reproductions and illustrations for books and magazines. It has long been replaced by photography in its commercial applications and, partly because of the difficulty of learning the technique, is much less common in printmaking, where it has been largely replaced by etching and other techniques. Other terms often used for engravings are copper-plate engraving and Line engraving. These should all mean exactly the same, but especially in the past were often used very loosely to cover several printmaking techniques, so that many so-called engravings were in fact produced by totally different techniques, such as etching.