Historical diagram showing "wheels that groove the lead" at a rolling and slitting mill for lead strips. From Zonca's Nuovo Teatro di Machine et Edificii, c. 1607. This is a diagram of an engraver's press for printing drawings with engraved copper plates. The copper plate rests between the board (C) and the backing felt (D). Wooden bearing blocks (B) hold the rollers firm. In Zonca's roller-press, the lower roller is driven in the opposite direction to the upper one by the friction of the board rolling over it. Illustrations improved in the 16th century thanks to the roller-press and copper-plate, which could bear more detail.