Fonts and formatting
Why is there a square box in my edited PDF?
Updated 2026-09-17 · 2 min read
That box — sometimes called tofu — means the reader was asked to draw a character code the font does not define.
It happens most often with spaces, because many PDFs express gaps as positioning instructions rather than space glyphs.
PDFfont edits PDF text in the document's own embedded font — no white cover boxes.
Edit a PDFHow it is avoided
Whitespace should never be drawn as a glyph in a subset font. Writing every space as numeric positioning inside the text operator matches how the original document expresses its own spacing, so no placeholder can appear.
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