Pattern welding is the practice in sword and knife making of forming a blade of several metal pieces of differing composition that are forge-welded together and twisted and manipulated to form a pattern. Often incorrectly called Damascus steel (which is produced by a different process), blades forged in this manner often display bands of slightly different colouration along their entire length. These bands can be brought out for cosmetic purposes by proper polishing or acid etching. Originally, pattern welding was used to combine steels of different carbon contents, providing the desired mix of hardness and toughness needed for highly demanding tasks such as cutting through armour. Although modern steelmaking processes negate the need to blend different steels, pattern welded steel is still used by custom knifemakers for the cosmetic effects it produces. Now, Jim Hrisoulas, author of The Complete Bladesmith, reveals the secrets of this ancient craft, from the welding of the starting billet to final assembly of the completed blade. Learn basic patterns and stunning, complex designs. Photos and illustrations