Replace by glyph ID
Each user outline replaces the original outline at the same glyph ID. Untouched glyphs and unrelated tables remain byte-for-byte identical wherever possible.
Rebuild the required tables
Changing outlines requires new glyf data and loca offsets. Metric edits may require hmtx updates, while head, table checksums, and the SFNT directory must reflect the rebuilt binary.
Block unsafe exports
Font Studio rejects incomplete contours, out-of-range coordinates, broken offsets, and invalid checksums. Glyph IDs remain fixed so existing shaping references continue to target the intended records.
TTF and WOFF2 downloads
TTF export rebuilds changed TrueType outlines while preserving unrelated source tables. WOFF2 export compresses that validated TTF in the browser, producing a web font without uploading the project to a conversion service.