Unembed PDF base14 fonts in LaTeX

🤔Why

The PDF specification requires that a PDF viewer/printer/whatever must have the base 14 fonts embedded. Because of this, there is not need for an application to embed those fonts in a document.

🌟Benefit

1. Reduce file size.
2. Make the text editable in PDF editors (Adobe Acrobat can recognize base14 fonts, so can edit most of texts without switching to a different font).

⚠️Danger

Symbol font (\sum and \prod and greek letters) despite being one of base14 fonts, does not work in MS Edge and Adobe Acrobat.

But it works in SumatraPDF and Mozilla PDF.js and Firefox and Chrome.

I guess this is because the symbol character set, also known as 259 – Symbols, Set 7

pdffonts output

As you can see from the emb column, PDF base14 fonts (including Times, Courier, Symbol) are not embedded.

name	type	encoding	emb	sub	uni	object	ID
Times-Roman	Type 1	Custom	no	no	yes	4	0
Times-Italic	Type 1	Custom	no	no	yes	5	0
Courier	Type 1	Custom	no	no	yes	6	0
Times-Bold	Type 1	Custom	no	no	yes	7	0
Symbol	Type 1	Custom	no	no	yes	8	0
YEELVS+CMSY10	Type 1C	Builtin	yes	yes	yes	9	0
SEBDKK+CMMI10	Type 1C	Builtin	yes	yes	yes	10	0
OKFTUL+rsfs10	Type 1C	Builtin	yes	yes	yes	11	0
WWNUGL+MSBM10	Type 1C	Builtin	yes	yes	yes	12	0
ATPFCN+CMEX10	Type 1C	Builtin	yes	yes	no	13	0

How to compile

1. load the project into Overleaf
2. select latex engine
3. compile

Note

Latexmk is used by Overleaf to control the compilation of your source LaTeX document into the final typeset PDF file. By using a customized configuration file called Latexmk you can override the default compilation commands to allow Overleaf to compile your document in a special way: In this project, first latex produces a dvi file, then dvipdfmx runs with the file fontmap as font map.

File size comparison

	size
original	102 KB
processed	13.4 KB

Differences: The original PDF is compiled by pdflatex engine (with default font map) and without mathastext package.