Tracer Controlled. A machine using a stylus following the indentations of a hard metal pattern – or template – to convey information to perform some metalworking operation as milling, engraving or forming. All pantographs and most machine engravers are tracer controlled. The mechanism is mechanical and dates from the 18th century.

Tracer controlled engraving is a low-cost, fairly quick method of die engraving

(in comparison with either hand engraving or modeling a design oversize and having it reduced on a die-engraving pantograph). Dies made by tracer controlled machine engraving are somewhat flater, stiff and mechanical; while modeled dies can be softer, more lifelike and can have higher relief.

In the numismatic field, most tokens, souvenir, token-like medals are tracer controlled engraved.

Attempts to replace tracer control with data processing – coupled with laser cutting – have met with great success by the end of the 20th century, however the earlier mechanical techniques are still in use. See machine engraving.