Rules on rulers for proofreading course students


Some proofreading course learners ask whether they need specialist rulers when they check printed documents.

Our online proofreading course uses the BSI proofreading symbols, and some marks may require exact measurements to be expressed in picas (symbols C10, C11 and C17).

We don’t recommend pica rules, or ems rulers, in our course materials, as they’re rarely used these days.

Most people measure in millimetres. Although the BSI symbols still refer to picas etc, this doesn’t reflect the reality of the broader publishing world.

All desktop publishing packages measure these types of spaces in mm. They do, however, still use a few of the fashioned printing terms such as Point sizes.

So our advice is to only purchase a Pica/ Ems ruler if you need one.

See our proofreading courses