Carve lines (line drawing)

Tetra pak is a very easy material to engrave. You can use a dry point: ceramic is the softest, carbide almost the same. The incisive carbide grips much more, which is less good for the thin line, but often pleases for the grip. The printed lines are very close.

You can also use a very fine agate burnisher, which allows for more flexibility in the gesture, and a softer and slightly wider line.