| Abstract from DBPedia | Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other types of material. As a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of modern variants such as microfabrication etching and photochemical milling it is a crucial technique in much modern technology, including circuit boards. In traditional pure etching, a metal plate (usually of copper, zinc or steel) is covered with a waxy ground which is resistant to acid. The artist then scratches off the ground with a pointed etching needle where the artist wants a line to appear in the finished piece, exposing the bare metal. The échoppe, a tool with a slanted oval section, is also used for "swelling" lines. The plate is then dipped in a bath of acid, known as the mordant (French for "biting") or etchant, or has acid washed over it. The acid "bites" into the metal (it undergoes a redox reaction) to a depth depending on time and acid strength, leaving behind the drawing (as carved into the wax) on the metal plate. The remaining ground is then cleaned off the plate. For first and renewed uses the plate is inked in any chosen non-corrosive ink all over and the surface ink drained and wiped clean, leaving ink in the etched forms. The plate is then put through a high-pressure printing press together with a sheet of paper (often moistened to soften it). The paper picks up the ink from the etched lines, making a print. The process can be repeated many times; typically several hundred impressions (copies) could be printed before the plate shows much sign of wear. The work on the plate can be added to or repaired by re-waxing and further etching; such an etching (plate) may have been used in more than one state. Etching has often been combined with other intaglio techniques such as engraving (e.g., Rembrandt) or aquatint (e.g., Francisco Goya).エッチング（英: Etching）または食刻（しょっこく）とは、化学薬品などの腐食作用を利用した塑形ないし表面加工の技法。使用する素材表面の必要部分にのみ（防錆）レジスト処理を施し、腐食剤によって不要部分を溶解侵食・食刻することで目的形状のものを得る。 銅版による版画・印刷技法として発展してきた歴史が長いため、銅や亜鉛などの金属加工に用いられることが多いが、腐食性のあるものであれば様々な素材の塑形・表面加工に応用可能である。 金属の試験片をナイタール（エタノールと硝酸の混合液）などの腐食液によって表面を腐食することで、金属組織の観察や検査などに用いられている。 (Source: http://dbpedia.org/resource/Etching) |
