cradle

…later an instrument called a cradle, or rocker, was used. It resembles a small spade with a toothed edge, and its cutting action throws up rough ridges of metal called burrs. The burrs are scraped away in places intended to be white in the finished print. In the 21st century,…

The tool used is the rocker, a blade with a curved serrated edge. The rougher the rocker, the heavier is the burr. The rocker is held with its cutting edge at a right angle to the plate, and the curved edge is rocked systematically over the entire surface. If this…