For Hochöfen, the Bechers consolidated black and white photographs of the industrial-age blast furnace. Striking and severe, these large scale structures were photographed from multiple angles in an analytical approach borrowed from the natural sciences. In their 1990 book, the artists described their fascination with the subject matter: "With some large industrial structures aesthetic additions are possible to a certain extent, but with blast furnaces heat, pressure, and gas generation overrule aesthetics. The blast furnace is like a body without a skin. Its insides are visible from the outside, organs, arteries and skeleton create its form."