Traditionally two main engraving methods were used: etching the surface with acid or scratching a design using hand-tools. The Pantograph method was a large-scale version of manual etching. It superseded earlier hand etching techniques but is being replaced by computer engraving.
The simplest pantograph comprises four horizontal bars and holds a pencil. Moving the end of one bar over the outline of a design causes the pencil in a connected bar to duplicate the same shape. Replacing the pencil with an electronic engraving tool attachment, patterns traced by one end of the bar are now etched into an object by the engraving tool at the other. The size of the etched design can be varied according to the placement of the engraving tool relative to the tracing arm.
The pantograph made hand engraving quicker and results more consistent. Rigid bars with high-quality pivot joints ensured accuracy. The engraving tool cut designs smoothly and speedily.
Thomas Jefferson used an elaborate pantograph to duplicate his correspondence. Today Jefferson's original pantograph is on display at Monticello, in Virginia.