Using the sketch as a guide, a full-size charcoal drawing, called a cartoon, is prepared.

With the cartoon, the cutlines or leadlines (where the glass will be cut) will be determined. Two carbon copies of this lead-line pattern are made. One pattern is cut into pieces using double-bladed scissors, which simultaneously cut away a narrow strip of paper from the middle of the leadline. This allows sufficient space for the core of the lead between the two pieces of glass. The glass cutter uses each piece of paper as a pattern to cut by.