# ugly math in preview of Wikipedia pdfs

When I "download as PDF" a Wikipedia article with math, such as Septic_equation, and open it in preview 8.0 on macos 10.10, the math formulas are ugly / munged:

instead of like in the browser (firefox) page

Before starting down the rocky road "what's wrong: fonts, preview, versionitis ..." let me ask

• does anyone else have the same problem
• are there print-ready .pdf or maybe .tex (not .html) for Wikipedia pages somewhere ?

This page in a nutshell: There exist at least three different forms of math formulae on Wikipedia pages, with at least seven ways to present them. None is completely satisfactory.

However I have no idea which ones are used in which articles, so which ones survive math -- pdf -- preview -- print. (Test cases for the 3 or 7 ways would be useful.)

Fonts might be a red herring, but here's pdfinfo, pdffonts anyway --

pdfinfo Septic_equation.pdf  # http://www.xpdfreader.com

Creator:        Chromium
Producer:       Skia/PDF m83
Tagged:         no
Form:           none
Pages:          3
Encrypted:      no
Page size:      594.96 x 841.92 pts (A4) (rotated 0 degrees)
File size:      673156 bytes
Optimized:      no

pdffonts Septic_equation.pdf  # all embedded ?
name                                           type              emb sub uni prob object ID
---------------------------------------------- ----------------- --- --- --- ---- ---------
LiberationSans                                 CID TrueType      yes no  yes           7  0
LiberationSerif-Italic                         CID TrueType      yes no  yes           8  0
LiberationSerif-Bold                           CID TrueType      yes no  yes           9  0
LiberationSerif                                CID TrueType      yes no  yes          10  0
LiberationSans-Bold                            CID TrueType      yes no  yes          11  0
LiberationSans-Italic                          CID TrueType      yes no  yes          85  0


When I export this in preview, the export.pdf is bigger ??

Creator:        Preview
Producer:       Mac OS X 10.10.5 Quartz PDFContext
Tagged:         no
Form:           none
Pages:          3
Encrypted:      no
Page size:      595.276 x 841.89 pts (A4) (rotated 0 degrees)
File size:      888908 bytes
Optimized:      no

name                                           type              emb sub uni prob object ID
---------------------------------------------- ----------------- --- --- --- ---- ---------
ZWJFYX+LiberationSans-Bold                     CID TrueType      yes yes yes          14  0
VOJIYC+LiberationSans                          CID TrueType      yes yes yes          10  0
VBAANE+LiberationSerif-Bold                    CID TrueType      yes yes yes          12  0
ESNUES+LiberationSerif-Italic                  CID TrueType      yes yes yes          11  0
CQEMAV+LiberationSerif                         CID TrueType      yes yes yes          13  0
POYZKZ+LiberationSans-Italic                   CID TrueType      yes yes yes          31  0

• Could you use a wikimedia to tex conversion tool to bypass the problem? Sep 2, 2020 at 10:11
• Why still Yosemite? No Mac is stuck at Yosemite. I'd at least try El Cap & see if things improve. Sep 2, 2020 at 10:17
• update your browser or you viewer PDF Sep 2, 2020 at 10:17
• On second thoughts, don't bother. I just tested & it still looks pants in El Cap. It's fine in Mojave, though. Sep 2, 2020 at 10:17
• "waste time and €€€ updating" There's no €€€ involved. All macOS updates are free. Your limit might be how far you can update the Mac. Knowing precisly which model it is would help that decision. Currently, your machine is so far out of support everything is going to be hit & miss. Sep 2, 2020 at 10:23

I have preview 11.0 and MacOS 10.15.6. I see no such issues. I would recommend upgrading.

• FWIW, I'm on Mavericks and I don't have the OP's problem in Preview. Tested with the same Wikipedia page. So if the issue is caused by OP's version of macOS, the bug was actually introduced in Yosemite. But I think it could just as easily be caused by GPU model or something. Sep 3, 2020 at 12:00
• I don't really see how a GPU bug can affect LaTeX/MathJax rendering, but then again I'm no expert in GPUs Sep 3, 2020 at 12:49

The problem may be that some equations are .svg images, and that

• html glyph pixels -> pdf pixels
• svg image pixels -> pdf pixels

rescale the pixels differently, in different versions of Preview.
(In Safari, drag the top equation in Wikipedia Septic_equation to a text window:

https://wikimedia.org/api/rest_v1/media/math/render/svg/17883fd69a7ee4f30b5185aac4c62a539158851a


With Color Meter, the "x" in the top equation is 8 pixels high in the browser, but 6 high, fat and ugly, with Preview 8.0, macos 10.10, on my 1920 x 1080-pixel screen.

How should rescaling of mixed html - svg pixels all the way to different screens / printers work ? Not easy.

• Can you provide the PDF that you have? Sep 3, 2020 at 18:50
• @Skeleton Bow, of course, where's an easy place to put them ? There are 2, from "download pdf": Septic_equation-10.10-download.pdf 673156 bytes, and "printable version" Septic_equation-10.10-print.pdf 488516) Sep 4, 2020 at 16:07
• @Skeleton Bow, pdfhost.io/v/IRlLIFk6E_Septic_equation1010downloadpdf.pdf and pdfhost.io/v/BAxcSPN7Y_Septic_equation1010printpdf.pdf. (But don't spend much time on it -- better things to do than chase old old bugs) Sep 4, 2020 at 16:47
• Definitely quite strange. Have you tried other PDF viewers? Sep 5, 2020 at 10:26
• Thanks @Skeleton Bow, good idea -- Adobe\ Acrobat\ Reader\ DC.app for 10.10 prints better, not fat (must have its own print driver) but not as nice as in the browser -- mathml ? An overview of the whole process of rendering html with images, mathml / mathjax ... + screen or printer parameters would be useful. Sep 6, 2020 at 10:09