How to Set Strikeout Position in FontForge

This guide explains the purpose of the strikeout position metric in digital typography and provides step-by-step instructions for locating and configuring it within FontForge. You will learn how this metric controls text strikethrough rendering across operating systems and where to input the correct values in the font’s metadata.

What is the Strikeout Position Metric?

The strikeout position metric defines the vertical placement of the horizontal line used when text is styled with a strikethrough effect. In OpenType and TrueType font specifications, this value is stored as yStrikeoutPosition in the OS/2 table.

Measured in font design units relative to the baseline, a positive value places the strikeout line above the baseline, while a negative value places it below. In most well-designed fonts, the strikeout position is set so the line passes through the optical center of lowercase glyphs, typically sitting around half or two-thirds of the font's x-height. This metric works in tandem with yStrikeoutSize, which dictates the thickness of the line. Setting these values properly ensures word processors, browsers, and layout software render consistent, visually balanced strikethroughs rather than relying on automated fallback positioning.

How to Configure Strikeout Position in FontForge

You can configure the strikeout position and its thickness directly through FontForge's Font Info dialog:

  1. Open your font project in FontForge.
  2. Navigate to the top menu and click Element, then select Font Info (or use the shortcut Ctrl+Shift+F on Windows/Linux, Cmd+Shift+F on macOS).
  3. In the left-hand category panel of the Font Info window, click on OS/2.
  4. In the tabs that appear at the top of the OS/2 panel, select the Metrics tab.
  5. Locate the Strikeout section on this pane. You will see two fields:
    • Position: Enter the vertical offset (in font units) from the baseline to the top of the strikeout line.
    • Size: Enter the desired thickness of the strikeout stroke (often matching the weight of the font's regular horizontal stems).
  6. Click OK at the bottom of the window to apply your changes to the font database.