How to Export a Symbol Font from FontForge

Exporting a symbol or icon font in FontForge requires specific configuration to ensure that non-alphanumeric glyphs render reliably across various operating systems, design applications, and web browsers. This guide covers how to set the proper font encoding, map glyphs to the Unicode Private Use Area, validate vector outlines to prevent rendering bugs, and generate standard font formats such as TrueType (TTF), OpenType (OTF), and web fonts.

Step 1: Set Encoding and Mapping

Symbol fonts should generally be mapped to standard Unicode code points or the Private Use Area (PUA) to prevent conflicts with standard text rendering.

  1. Open your project in FontForge.
  2. Go to Encoding in the top menu and select Reencode > ISO 10646-1 (Unicode, BMP). This provides access to standard Unicode ranges.
  3. If your symbols represent custom icons rather than standard Unicode symbols, place them in the Unicode Private Use Area (PUA) starting at U+E000 through U+F8FF. Mapping to the PUA prevents screen readers and system fallbacks from misinterpreting your icons as standard text characters.
  4. If you intend for the symbols to be typed directly via standard keyboard keys without special software, map your glyphs to standard Latin code points (e.g., U+0041 for "A", U+0061 for "a").

Step 2: Configure Font Information

Incorrect font classifications can cause operating systems to ignore glyphs or apply incorrect line heights.

  1. Navigate to Element > Font Info.
  2. Under the PS Names tab:
    • Set the Fontname, Family Name, and Name for Humans clearly (avoid special characters or spaces in the Fontname field).
  3. Under the OS/2 tab:
    • Go to the Char/Freq sub-tab. Ensure the character metrics accurately reflect the ranges you used (click Set to automatically detect glyph ranges).
    • Go to the Panose sub-tab. Set the Family Kind to Pictorial or No Fit, which signals to the OS that the font consists of symbols.
  4. Under the General tab:
    • Ensure the Em Size is set properly (typically 1000 for PostScript/OTF or 1024/2048 for TrueType/TTF).
  5. Click OK to save your changes.

Step 3: Clean and Validate Outlines

Corrupted paths and incorrect winding directions cause rendering artifacts or completely missing glyphs in exported files.

  1. Select all glyphs in your font (Ctrl + A or Cmd + A).
  2. Correct the path directions by going to Element > Correct Direction (Ctrl + Shift + D).
  3. Merge overlapping paths by selecting Element > Overlap > Remove Overlap (Ctrl + Shift + O).
  4. Snap points to whole coordinate values by choosing Element > Round > To Int.
  5. Run the validation tool under Element > Validation > Find Problems to identify and fix unclosed contours, missing points at extrema, or self-intersecting lines.

Step 4: Export the Font File

Once the outlines and metadata are configured, generate the final binaries.

  1. Go to File > Generate Fonts.
  2. Select the destination folder and name your file.
  3. Choose the target format from the dropdown:
    • OpenType (CFF) (.otf) for vector-heavy symbols and design work.
    • TrueType (.ttf) for native Windows support and general desktop use.
    • Web Open Font Format (.woff / .woff2) for website integration.
  4. Click the Options button next to the format dropdown:
    • For TrueType, ensure TrueType Hints are generated if needed, or leave unhinted for flat vector icons.
    • Check OpenType to include standard OpenType layout tables.
  5. Click Generate.
  6. If a warning dialog appears regarding non-standard glyph names or minor validation errors, review the report. Warnings regarding missing characters (such as basic alphanumeric letters) can safely be ignored if you are building an exclusively symbolic font.