Fonts

vellora uses the same bundled fonts on every machine and never reads fonts installed on the host, so there are no surprise font swaps between your laptop and your server.

Without any setup

The CSS generic families map to bundled fonts:

You write	You get
font-family: sans-serif	Liberation Sans (DejaVu Sans fills in characters it lacks)
font-family: serif	Liberation Serif
font-family: monospace	Liberation Mono

Liberation fonts have the same character widths as Arial, Times New Roman and Courier New, so text in templates written for those fonts takes up the same space.

Each Liberation family includes regular, bold, italic and bold italic, so font-style: italic, <em>, <i> and <b><i> print slanted, as in Chrome. font-style: oblique uses the italic face too; an oblique angle under 14deg stays upright, as Chrome draws it. vellora doesn't fake a slant: characters that fall back to DejaVu Sans stay upright in italic text.

Your brand font

Read the font files and pass the bytes in fonts. Then use the font's own family name in CSS:

import { readFileSync, writeFileSync } from "node:fs";
import { renderPdf } from "vellora";

const html = `<!DOCTYPE html>
<html>
  <body style="font-family: 'Inter', sans-serif">
    <h1>Hello, {{ name }}</h1>
    <p>Set in your brand font.</p>
  </body>
</html>`;

const pdf = await renderPdf(html, { name: "Ada" }, {
  fonts: [
    readFileSync("./fonts/Inter-Regular.ttf"),
    readFileSync("./fonts/Inter-Bold.ttf"),
  ],
});

writeFileSync("branded.pdf", pdf);

Each weight and style is its own file. Pass the regular, bold and italic files you use, and vellora picks the closest match for each font-weight and font-style. TTF and OTF both work.

Coming from @font-face?

vellora doesn't load @font-face rules or their src URLs, and it doesn't let you rename a font. Pass the bytes in fonts and write the name the font file itself declares. If the name doesn't match, the text falls back to the bundled font without an error. To see a font's name, open it in your system's font viewer, or on a machine with fontconfig run:

fc-scan --format "%{family}\n" Inter-Regular.ttf

Errors

• A fonts entry that isn't a Uint8Array (a Buffer is fine) throws VelloraInputError.
• Bytes that aren't a font throw VelloraUnsupportedError with feature: "font:invalid", naming the position in the array, for example fonts[0].

Rules and limits

• Your fonts never replace the generic families: sans-serif always means the bundled font. Your font is used only where CSS names it.
• A font you pass but never reference leaves the PDF unchanged.
• Not supported: @font-face aliases, loading font URLs from CSS, overriding a font's weight or style, choosing variable-font axes, and font-subsetting options.

Next step

Make an archival PDF/A file →