How to take a rubbing of a frame or engine number

The problem it solves

Some stampings simply will not read. They are shallow, filled with paint, at an angle you cannot get a light onto, or in a recess where a phone will not focus. People give up and conclude the number is gone, when it is right there and merely illegible.

A rubbing is the oldest trick for reading an impression in metal and it is still the best. Paper over the stamping, the side of a soft pencil across it, and the raised areas take graphite while the stamped depressions stay pale. The result is often dramatically clearer than the metal itself, because it converts a depth difference — which your eye reads badly in poor light — into a contrast difference, which your eye reads very well.

It works where a photograph fails, because a camera also relies on light and shadow and cannot get into a recess. And it produces a physical record you can carry, post or scan, which a squint at a crankcase does not.

This sheet is the paper. It is deliberately plain in the rubbing areas, with the technique on the facing side, so it can be printed on thin paper and used as intended.

The mistakes this sheet exists to prevent

• Using a hard pencil, which cuts the paper instead of shading it.
• Using the tip rather than the side of the lead, which gives lines instead of a field.
• Not cleaning the stamping first, so the rubbing records dirt rather than characters.
• Pressing so hard that the paper tears into the deepest characters.
• Not writing down where on the machine the rubbing came from, which makes it useless later.

How to use it

1. 01Clean the stamping and dry it before you start.
2. 02Hold the paper firmly so it cannot shift halfway through.
3. 03Use the side of a soft pencil, moving in one direction across the whole area.
4. 04Label each rubbing with where on the machine it came from, immediately.