PPT Font Fix

Problem

PowerPoint's "Export to PDF" can fail to embed downloaded/custom fonts, substituting built-in defaults, even when:

• Fonts are properly installed and embeddable
• "Embed fonts in the file" is checked in PowerPoint options

Workaround

Applying a tiny transparency (1%) to text with 0% transparency forces PowerPoint to correctly embed fonts in PDF output. This is visually imperceptible but changes how PowerPoint processes the font during export.

Usage

python3 scripts/fix_font_transparency.py input.pptx [output.pptx] [--transparency 1]

Options

• output -- Output PPTX path (default: input_fixed.pptx)
• --transparency, -t -- Transparency % to apply (default: 1)

Behavior

• Only patches text runs that are fully opaque (0% transparency)
• Leaves text that already has any transparency untouched
• Safe to run multiple times
• Only modifies slide XML (ppt/slides/slideN.xml), not layouts/masters

Workflow

1. Receive PPTX file from user
2. Run the fix script: python3 scripts/fix_font_transparency.py input.pptx
3. Return the patched PPTX to the user
4. User opens patched file in PowerPoint and exports to PDF -- fonts now embed correctly

Note

PDF export must be done from PowerPoint desktop. Server-side converters (LibreOffice, Graph API) do not reproduce the same font embedding behavior.