In later times, this effect was often imitated by partially mixing various metals like copper together with the steel, forming mokume (wood-eye) patterns, although this was unsuitable for the blade itself. After the 14th century, more attention began to be paid to the patterns in the blade as an aesthetic quality. Intentionally decorative forging-techniques were often employed, such as hammering dents in certain locations, which served only to create a wood-eye pattern when the sword was filed and polished into shape, or by intentionally forging-in layers of high slag content.