Preparing a horizontal manuscript for KDP comes down to three things: chapter boundaries, a deliberate policy for full-width and half-width characters, and print-era phrasing like "see page 35". Horizontal flow does not decide which style is correct for your book, so set an editorial rule first and review the manuscript against it.
This article is for people writing practical and technical books horizontally. Preparing vertical manuscripts, and diagnosing garbled text, are covered separately.
Set an editorial rule for horizontal text
Full-width and half-width digits, bracket forms, and capitalisation can all be valid in context. The useful rule is not “convert everything,” but “keep the same role consistent while preserving quotations and proper names.”
Horizontal writing direction controls text flow; it is not a style-normalisation pass. Treat a half-width-character report as an inventory for editorial decisions, not as a list of automatically incorrect text.
Tidying by hand
The naive approach is rereading and fixing: normalising digits, normalising brackets, confirming chapter boundaries.
Others reach for search and replace — converting all full-width digits to half-width in one operation, say.
Bulk replacement over-corrects
The problem is that it changes places it should not.
Replace every full-width digit with a half-width one and you change not only body numerals but digits inside proper nouns and inside quoted passages. A quotation has to match its source, and it silently stops matching.
And bulk replacement is noticed after the fact. You undo repeatedly to get back, and other edits are rolled back along the way.
Chapter boundaries are the other issue. With all chapters in one file, something has to mark the divisions. Infer them from blank lines and the blank lines you inserted for pacing become chapter breaks.
rune Studio reports the count before replacing
rune Studio can search across a workspace and replace, and it can preview a replacement without performing it.
I verified this by driving the development build from the command line. Previewing a replacement returned two files and two occurrences, with the manuscripts unchanged. Running it changed one occurrence, and searching again found the replacement.
Because the count comes first, a number that does not match your expectation stops you. If you expected three and it says forty, forty includes places that should not change.
Half-width positions can be counted
There is also a function that reports where half-width characters occur. Running it on a manuscript returned six positions, each with the actual characters. Knowing what is half-width lets you survey the whole before normalising anything.
If your book's style guide calls for half-width alphanumerics in body prose, count the current state first and review each candidate. Preserve full-width forms where a quotation, proper name, or deliberate notation requires them.
Chapter boundaries are set with a page-break mark
To split one file into chapters, insert a page-break mark. Doing that placed the mark in the manuscript. Because it does not rely on blank-line counting, pacing blank lines never turn into chapter breaks.
The horizontal setting is verifiable in the exported file
Reading inside an EPUB exported with horizontal settings showed horizontal text flow and left-to-right page progression. A mix-up where you meant vertical and got horizontal can be caught before submission.
Rewrite every "see page 35"
In a reflowable horizontal EPUB, print-era positioning needs review. “See the diagram on page 35” and “as in the table on the previous page” are unstable because changing the type size changes where pages divide. Fixed-layout eBooks keep fixed pages and are a different case.
The fix is fixed: point by chapter and heading, or point by the name of the thing itself. "The diagram on page 35" becomes "the structure diagram in chapter two"; "the table on the previous page" becomes "the mapping table above".
This is cheapest to do while drafting. Hunting for them afterwards means collecting instructions scattered across chapters. Searching your manuscript once for the word "page" tells you immediately how many are left.
Who this suits, and who is fine without it
It suits practical, technical, and explanatory books set horizontally. The more alphanumerics and symbols, the more visible the inconsistencies.
A vertical novel is a different case with its own preparation; this article does not apply.
Scope note: what was verified is searching and replacing, reporting half-width positions, and the writing direction recorded in the exported file. Whether KDP accepts the result is outside this.
Summary
- Full-width and half-width choices follow an editorial rule; the half-width report is an inventory, not an automatic correction list
- Bulk replacement over-corrects, changing quotations and proper nouns
- rune Studio reports the affected count before replacing, and can count half-width positions
- Chapter boundaries come from page-break marks, so they never collide with pacing blank lines
For a first step, count the half-width positions in your manuscript once. Starting with the chapters that have the most is faster than rereading from the beginning.
See the current product scope on the Rune Studio product page.
