If you are asking how to create EPUB files and prevent garbled text, begin with a separately named source copy rather than the export button. The source must survive inspection, approved substitution, and reopening before it becomes an EPUB input.
To keep garbled characters out of EPUB export, start before export: isolate conversion candidates in a duplicate, decide each replacement from context, save a new UTF-8 source, and reopen it to reconcile both character count and zero unresolved candidates.
This guide uses a 2,100-character copy with five prepared candidates. It focuses only on making the text source safe; images and chapter order belong to separate checks.
Inspect a duplicate, not the only source
Keep manuscript-original.txt unchanged and create manuscript-encoding-check.txt. Record encoding, line ending, and character count before editing. The controlled source was UTF-8 with LF endings and 2,100 characters.
Overwriting the original while text is mis-decoded can destroy information you need for recovery. Treat the original as the comparison source and make all candidate changes in the duplicate.
Rune Studio’s published documentation describes detection of major Japanese encodings, surfaced unconvertible characters, and suspended autosave while such candidates remain. The safeguard does not determine the meaning of a replacement for you.
Separate the five decisions
Create one row per candidate: chapter and line, surrounding text, accepted result, and reason. A personal name, quotation, symbol, old character form, and organization name may all require different decisions.
The target is not simply “delete five warnings.” It is to preserve meaning for all five. A visually similar replacement can still alter a name or quotation.
Apply only approved substitutions
Change a candidate only after checking the author, source quotation, or house style. Leave uncertain cases unresolved instead of silently deleting them. Keep the original character, accepted character, and line location in the record.
Save the result under a new name such as manuscript-utf8-safe.txt using UTF-8. The separate filename preserves a return path if a later check reveals the wrong substitution.
Reopen and reconcile zero candidates with 2,100 characters
Close and reopen the safe copy. Confirm UTF-8, LF, 2,100 characters, and zero unconvertible items. Zero warnings with 2,099 characters may indicate that a character was lost during editing.
The controlled run reopened the approved UTF-8 copy at 2,100 characters with no unconvertible characters reported. That observation applies to the text source before EPUB generation.
Keep EPUB and ten checkpoints as an explicit next test
After creating the EPUB, select ten representative locations: the five repaired candidates plus punctuation, a long dash, a circled number, an old-form character, and another script-sensitive symbol. Inspect those locations in the generated package and in your target reader.
The current run did not perform that EPUB export or inspect ten artifact checkpoints. It stops at the verified reopened UTF-8 source. Do not read the 2,100-character result as proof that all ten locations render correctly in an EPUB; run that next test on your own duplicate.
Who benefits from this boundary
This method is useful for old text files, sources moved between operating systems, and novels containing rare names or historical forms. Even a source that begins in UTF-8 can benefit from the separate character-count comparison.
It does not solve missing images or incorrect navigation. Those require image-reference and package-structure checks of their own.
Conclusion: make the safe copy the export input
To create EPUB without carrying garbled characters into export, preserve the original, resolve five candidates by meaning, save a UTF-8 copy, and reopen it at the same 2,100-character count with zero unresolved items. Use that safe copy as the input to your separate EPUB test.
Start by building the candidate table on a duplicate. Current Mac features and download options are available on the Rune Studio website.
