Damascus steel in the context of Wootz steel

Pattern welding is a smithing practice of folding and/or twisting metal, possibly multiple pieces (which may have differing compositions, or be completely different types of metal) that are forge-welded. This results in differing layers in a pattern, hence the name. This process was independently discovered by many ironworking societies. Often wrongly called Damascus steel, blades forged in this manner display bands of slightly different patterning along their entire length. These bands can be highlighted for cosmetic purposes by proper polishing or acid etching. Pattern welding was an outgrowth of laminated or piled steel, a similar technique used to combine steels of different carbon contents, providing a desired mix of hardness and toughness. Pattern welding also, more importantly, reduces impurities and, most importantly, homogenizes the steel. However modern steelmaking processes negate the need to blend different steels, reduce impurities, or homogenize the steel, pattern welded steel is still used by custom knifemakers for the cosmetic effects it produces. It is also used with non-steel metals, for its aesthetic properties, such as with mokume-gane.