Which of the following pencil is used to trace a cephalogram?
The following armamentarium is required for a good tracing to be performed:

An X-ray illuminator/mounted on a tracing table with soft light. The tracing table should be mounted in a room with minimal brightness. The tracing table should also have a control switch for controlling the intensity of light.
Tracing paper of good quality. Pre-cut sheets are available in 8X10 inch size from orthodontic suppliers.
Sharp 7H pencil and HB pencil.
Geometric set squares and protractor.
Tooth templates, usually supplied by orthodontic suppliers.
Good quality dust free eraser and transparent adhesive tape.

The cephalogram is usually traced with a tracing paper mounted, keeping the face profile on the right side of the operator. Mount the tracing paper using adhesive tape, on the left-hand border of the cephalogram.
Ref: Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities, 3e, Om P. Kharbanda pdf no 956
2H
4H
7H
5H