Typesetting Styles
Twelve built-in styles ship with smaragd — the first eight follow US/Amazon-KDP trim conventions, the last four follow UK/European ones:
| id | Label | What it looks like |
|---|---|---|
manuscript | Manuscript | Plain submission format: US Letter, 1in margins, double-spaced, ragged-right (not justified), no running header or drop cap |
trade_paperback | Trade Paperback | 6×9in trim, justified body text, a running header (author’s name / current chapter), and a drop cap on each chapter’s first paragraph |
mass_market | Mass Market Paperback | 4.25×6.87in trim (the standard mass-market size), small 9pt justified type and tight margins to match, running header, drop cap |
digest | Digest | 5.5×8.5in trim — between Mass Market and Trade Paperback, common for novellas and shorter literary fiction — justified, running header, drop cap |
hardcover | Hardcover | 6.14×9.21in trim (KDP’s hardcover size), roomier margins and a larger drop cap for a more formal feel, sans-serif (Atkinson Hyperlegible) headings over a serif body, running header shows book title / current chapter |
academic | Academic | A4, 12pt, ragged-right (not justified — matches APA-style manuscript guidance), no running header or drop cap; for a thesis chapter or paper draft, not a book |
large_print | Large Print | 7×10in trim, 18pt Atkinson Hyperlegible (a sans-serif designed for low-vision readers) ragged-right body text, no drop cap or running header — accessibility features, not decoration |
chapbook | Chapbook | 5×8in trim, generous margins, ragged-right (justification would fight a poem’s own line breaks), no drop cap, running header shows author/title rather than a chapter |
uk_b_format | UK B-Format Paperback | 129×198mm — the standard UK trade paperback trim, distinct from (not a rescale of) the US 6×9in Trade Paperback — 10pt justified, running header, drop cap |
uk_a_format | UK A-Format Paperback | 110×178mm — the UK mass-market paperback trim, smaller and narrower than the US Mass Market Paperback — 9pt justified, running header, drop cap |
a5 | A5 Paperback | ISO 216 A5 (148×210mm exactly) — a common European trade/paperback trim, used as a book size in its own right rather than cut down from a larger sheet — 10pt justified, running header, drop cap |
manuscript_a4 | Manuscript (A4) | manuscript’s exact submission conventions (double-spaced, ragged-right, no header or drop cap) on ISO A4 instead of US Letter, for submitting outside North America |
Like color themes and plugins, custom styles are .toml files you author or drop into smaragd/styles/ inside smaragd’s config directory (no in-app style editor):
- Linux:
~/.config/smaragd/styles - macOS:
~/Library/Application Support/smaragd/styles - Windows:
%APPDATA%\smaragd\config\styles
A minimal custom style:
id = "novella"
label = "Novella"
[page]
width_mm = 139.7 # 5.5in
height_mm = 215.9 # 8.5in
margin_mm = 15.0
[body]
font = "Libertinus Serif"
size_pt = 11
line_height = 1.2
justify = true
[headings]
font = "Libertinus Serif"
sizes_pt = [22, 19, 16, 14, 13, 12]
[blockquote]
font = "Libertinus Serif"
size_pt = 11
italic = true
[code]
font = "DejaVu Sans Mono"
size_pt = 10
id and label are required, along with the [page]/[body]/[headings]/[blockquote]/[code] tables — id is what selects the style and is lowercased automatically. sizes_pt needs all six sizes (one per heading level, h1–h6). Two more tables are optional:
[drop_cap]
scale = 3.0 # first letter renders at 3x body size
[running_header]
left = "{author}"
right = "{chapter}"
{title}/{subtitle}/{author} are substituted with whatever’s typed into the export dialog; {chapter} (supported as a whole side’s content, not mixed with other text) shows the current chapter on the print PDF specifically — DOCX and EPUB don’t have a per-page “current chapter” concept, so a {chapter} token is just left blank there.
“Libertinus Serif”, “DejaVu Sans Mono”, and “Atkinson Hyperlegible” (the built-in styles’ fonts) aren’t arbitrary choices — they’re guaranteed available to the PDF renderer specifically, bundled with smaragd itself rather than depending on what’s installed on your system. A custom style naming some other font still works for DOCX/EPUB (which just reference a font by name, the same way any other document does — Word/an e-reader substitutes if it’s not installed), and for PDF too if that font happens to be installed locally; if not, the PDF falls back to some available font rather than failing the export.
Using your own font file
Naming a font that isn’t one of those three works for DOCX/EPUB/PDF as above, but the Preview tab can’t render it — it only knows the fonts actually installed with smaragd, so it falls back to a generic face on-screen even though the exported file uses the real font.
To make Preview (and PDF, without needing the font separately installed as a system font) use your own font file too, add a font_file key alongside font in any of [body]/[headings]/[blockquote]/[code]:
[body]
font = "My Custom Font"
font_file = "MyCustomFont.ttf"
size_pt = 11
font_file accepts a .ttf or .otf file, either as an absolute path or (as above) relative to the style’s own .toml file — so you can keep a style and its font side by side in smaragd/styles/ and reference it by filename alone. font is still what DOCX/EPUB write into the document and what the file is registered under for Preview/PDF, so keep it a real, sensible font name — it’s what a reader without the font installed will see substituted. Reload Custom Styles picks up a new or edited font_file the same as any other style change; a file that doesn’t exist or isn’t a valid font is skipped with an error message (that one font slot falls back to a generic face) rather than blocking the rest of the style from loading.
A relative font_file resolves against wherever that particular .toml file lives, which in turn lives in the OS-specific styles folder from the list above (Linux ~/.config/smaragd/styles, macOS ~/Library/Application Support/smaragd/styles, Windows %APPDATA%\smaragd\config\styles) — so font_file = "MyFont.ttf" always means “next to this style file” on every platform, no path syntax to adjust. An absolute path, though, is tied to the OS it was written for (/home/you/Fonts/MyFont.ttf vs. C:\Fonts\MyFont.ttf) and isn’t portable if you copy the style file to a different machine running a different OS — a path that isn’t recognized as absolute on the machine it’s loaded on is silently treated as relative instead (almost certainly not the file you meant), rather than erroring. Keeping the font next to the style and using a relative path avoids this entirely, and is the recommended approach if you ever share or sync your smaragd/styles/ folder across machines. Filesystem case-sensitivity is a related wrinkle: Linux is case-sensitive, macOS and Windows normally aren’t, so a font_file whose case doesn’t exactly match the real filename can still work on macOS/Windows but fail to be found on Linux.
Use Reload Custom Styles in the export dialog to pick up a new or edited .toml file without restarting. A style file that fails to parse, or whose id collides with an already-loaded style (built-in or another custom one — whichever loaded first wins), is skipped with an error message rather than stopping other styles from loading.