BLUNDELL HARLING A4 PICA TYPE SCALE

Pica Type Scale [also known as a line gauge or E-scale], a specialized ruler used by graphic designers, typographers, and printers to measure text and layout elements.
Before digital design software became the norm, these physical scales were essential tools for copyfitting—calculating how much space a certain amount of text would occupy on a printed page.

How to Read This Scale
The scale is divided into columns, each corresponding to a specific Point Size [the vertical height of a line of text, including the space above it].

Point Size Columns [9, 10, 11, 12]: These columns allow you to measure leading [the vertical distance from the baseline of one line of text to the next]. If you place the ruler against a block of printed text and the lines align with the marks in the 10 column, you know the text is set with 10-point leading.

The Numbers [1, 2, 3…]: These represent the number of lines. For example, if you look at the 12 pt column and see the number 10, it indicates the total height of 10 lines of 12-point type.
Inch Scale: On the far right, there is a standard inch ruler for general measurements.

Why Designers Use It
Measuring Leading: Quickly determining the line spacing of a printed sample.
Copyfitting: Estimating how many lines of text will fit into a specific vertical area.
Layout Planning: Ensuring that margins and columns are mathematically consistent with the type size being used.