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Fraction bars disappear when printing webpages into PDFs.

See original GitHub issue

Hello, I’m using KaTeX 0.10.0-beta and a fresh installation of Google Chrome Beta 69.0.3497.23 on Ubuntu 18.04 (to make sure that all preferences are defaults). I’m considering printing webpages with math formulas into PDFs. But I came across some issues with fractions.

For example:

<!DOCTYPE html>
<html>
<head>
  <link href="katex/katex.min.css" type="text/css" rel="stylesheet">
  <script src="katex/katex.min.js" type="text/javascript"></script>
  <script src="katex/contrib/auto-render.min.js" type="text/javascript"></script>
  <script>
    document.addEventListener("DOMContentLoaded", function() {
      renderMathInElement(document.body, options = {delimiters: [{ left: "$$", right: "$$", display: true }, { left: "$", right: "$", display: false }]});
    });
  </script>
</head>
<body>
<p>inline math: ${2 \over n}$.</p>
<p>display math:
$$
f^{(n)}(x) = \begin{cases}
x + nb &amp; (a = 1) \\
a^n\ x + {a^n - 1 \over a - 1} \cdot b &amp; (a &gt; 1)
\end{cases}
$$
</p>
</body>
</html>

Print it via Chrome and will get:

Press “F12” to add the following CSS code:

.katex {
    font-size: 1em;  /* or even smaller */
}

Reprint and get:

I have also tried https://khan.github.io/KaTeX/ and set font-size to 0.3em and came across the same issue. I wonder why printed PDFs would be different from original webpages. Is that a bug in Chrome or KaTeX?

Issue Analytics

State:
Created 5 years ago
Comments:11 (3 by maintainers)

Top GitHub Comments

1reaction

ronkokcommented, Aug 14, 2018

@mbourne Thanks for the feedback. I’ve re-opened the PR.

0reactions

mikepiercecommented, Dec 15, 2022

I’m going to close this issue, as resolved by PR #1594. We may get a complaint someday for frac-bars that print too thick, but that will be a different issue.

I came here looking to complain about exactly that 😉

08December2022-1670551638

That’s a screenshot of PDF, printed from a webpage, of an in-line fraction.

Update before I leave for winter: Here’s screenshots of a PDFs created by chrome-beta (left) and by firefox (right) with only CSS specifying 9pt font.

screenshot

@media only print {
    body {font-size:9pt;}
}

Increasing the font-size to 12pt got rid of the visual difference. This isn’t a serious problem for me though, and looking through the issues y’all know about this.