Help Me Understand How Fonts are “Embedded” in a Document

[LSL2026]

This just came up on another forum.

A user exported a file they had created in MuseScore, uploaded it to MuseScore’s site and the font for their title displayed incorrectly.

The user was surprised, as was I, that it “substituted” another font.

It was explained that, since the uploaded file is not a PDF or image file, it only displays fonts that are in the end user’s system. So basically it sounds like the server running MuseScore that plays these files back in this kind of dedicated interface simply doesn’t have the font the user used and it substituted something else instead.

I get that. I download a MS score from someone else, but I don’t have Sebastian installed, it’s probably going to substitute Leland and the same is true for any text fonts it has. I mean, I know this - I just got a new computer, and that edited Maestro font I just created a couple of days ago isn’t on it yet and it displays the scores in regular old Maestro.

____

But what about a PDF?

When I post a PDF here, and you guys download it and look at it, you’re seeing it “as it was exported”.

But here’s the question - I HAVE come across PDF files that pop up a “X font is unavailable” warning message.

So do PDFs have to or can only use fonts installed on an end user’s system?

I’ve seen that happen, so that kind of makes sense - making it more like any kind of MSWord or text file.

But what about the notes?

I mean you send a PDF to a user that doesn’t have Leland or Maestro or whatever installed in their system and they can see the notes fine. I have students do this all the time on their tablets and what not.

I’ve been using TNR for my text, so obviously that’s common on all systems now so I’m probably not noticing if it’s changing slightly from a MacOS to iOS or Android etc.

But they can see the notes fine and they don’t have Leland etc.

So what am I missing here? Do PDFs “embed” the fonts in them, or do they carry them along with them and secretly install them on your system when you download them?

Or why does the music work, and not the text? ( in a PDF if that’s true, I understand why it doesn’t work in the musescore file example I started with).

I have seen scores that will print on a printer in the old days that printed with all of the alphabetical characters - like is used Helvetica and had “q”s all over the place for quarter notes!!! And I have seen the occasional PDF someone’s posted online that does the same thing.

But it would be insane to pay for sheet music from Hal Leonard, or any of the places that sell PDF sheet music, and open it on your computer and it not render as advertised. That doesn’t seem to happen.

I am thinking that a MuseScore file is like a MIDI file, while a PDF is like an audio file.

Am I wrong?

Or are some places just converting the PDF to an image file that is “locked” with the right look - or is the exported file from MS an “image” rather than an “editable” PDF or something????

_____

And this makes me think: Would it be better to create scores in some image format to make sure all end users get the same look. SVG is scalable, but it’s also not a format a lot of things work with.

I’ve never really had any concerns or problems with PDFs, but the discussion made me curious since I’ve been customizing Maestro - are my end users going to see my fonts as intended. If they don’t have FreeSerif is it going to substitute TNR, or worse, Georgia and have them run off the page margins…If they don’t have Maestro on their system, what happens…

[Shinianqi]

As far as I know, the file uploaded to the MuseScore website is an .mscz file, not a PDF. This means the score is rendered from the score data rather than from a fixed page description like a PDF, which is also why features such as playback and piano-roll/waterfall views are possible.

The .mscz file itself does not contain the actual font files. When the score is opened, MuseScore looks for the corresponding fonts on the local system. If a font is not available, it falls back to a substitute font.

PDFs work differently. Most PDFs intended for distribution embed either the full font or a font subset (containing only the glyphs used in the document). As a result, the document usually displays exactly as intended even if the viewer does not have those fonts installed.

So in general, whether a PDF displays correctly depends on whether the necessary font data was embedded when the PDF was created.

[OCTO]

So in general, whether a PDF displays correctly depends on whether the necessary font data was embedded when the PDF was created.

Yes, and this information is stored within the font itself as a license, meaning that the font allows embedding into PDF.  In the rare cases embedding is not permitted.  This is not an issue with music fonts, as basically all music fonts on the market allow embedding and are thus included in the PDF.  

But this is not necessarily true for proprietary "in-house" fonts, like by Henle or Bärenreiter, you need to work on specific computers to use these fonts, and if they want to distribute their PDFs outside of "in-house" they simply outline all fonts, shapes, curves and lines, before exporting into PDF, making it impossible to extract these fonts.

When we say "embedded" it means exactly "into PDF", and not other document types.

[Shinianqi]

Thank you for your additional comments, OCTO.

I completely agree with these points. In particular, the practice of converting fonts and graphics to outlines when distributing proprietary "in‑house" fonts aligns perfectly with my own experience and understanding.

[LSL2026]

Yes, and this information is stored within the font itself as a license, meaning that the font allows embedding into PDF.  In the rare cases embedding is not permitted.  This is not an issue with music fonts, as basically all music fonts on the market allow embedding and are thus included in the PDF.  

Ahh, so this is why sometimes you still run across some PDF someone posts that all the notes have turned into letters and whatnot - it was some proprietary font (or possibly some form of copy protection) that wasn’t embedded.

This is all making sense now.

[jrethorst]

I think that some programs (Adobe Acrobat?) let you choose whether to embed fonts when you make a PDF. I think that other programs (Dorico?) embed fonts in any case. I think Musescore limits (or used to limit) the fonts it uses so that users can trade files without needing to embed fonts.

[LSL2026]

I think that some programs (Adobe Acrobat?) let you choose whether to embed fonts when you make a PDF. I think that other programs (Dorico?) embed fonts in any case. I think Musescore limits (or used to limit) the fonts it uses so that users can trade files without needing to embed fonts.

Based on a discussion over at MS as well as here I believe it is embedding the font when you export as PDF - I can’t see how it wouldn’t.

[OCTO]

MuseScore did not allow the use of any fonts other than its own.  If you wanted to use a different font, you had to compile the software from the source code.  There was no way to tweak the software to use another font, nor could you edit the fonts that MuseScore used.  This was done to ensure that scores uploaded to MuseScore.com would always display correctly.

This has changed recently, and you can now create your own music font and use it in MuseScore.  However, if you upload a score to MuseScore.com, your custom fonts will not appear.  MuseScore files DO NOT embed fonts.

[benwiggy]

Fonts in PDFs are usually embedded as "subsets". This means only the characters used on the page are included. So, if there's no letter Z in your PDF, the data for that font's Z isn't there.

if they want to distribute their PDFs outside of "in-house" they simply outline all fonts, shapes, curves and lines, before exporting into PDF, making it impossible to extract these fonts.

Well, you can still use those outlines to create a new font, which is not much different from extracting the font subset. A subset will only gives you the glyph shapes: you won't get kerning data, ligature references, or any other metadata.

I’ve never really had any concerns or problems with PDFs, but the discussion made me curious since I’ve been customizing Maestro - are my end users going to see my fonts as intended. If they don’t have FreeSerif is it going to substitute TNR, or worse, Georgia and have them run off the page margins…If they don’t have Maestro on their system, what happens…

Fonts in PDFs are also given unique names, like "AXYQU+Helvetica-Regular", which basically ensures that the OS (or the printer) uses the copy in the document, rather than substituting with its own copy of Helvetica, if it has one.

I would say that 99.999% of PDFs have the fonts embedded, and if they don't, it's usually a computer error or a user mistake.

And this makes me think: Would it be better to create scores in some image format to make sure all end users get the same look. SVG is scalable, but it’s also not a format a lot of things work with.

Dear God, no. SVG's support for fonts is terrible. PDF is by far the best vector format. That's why it's such a success.