No matter what options I have tried, I haven’t managed to make mPDF to embed the Sun-Ext* fonts or a subset of it in the pdf file. I only managed to get the font embedded by adding the ‘sun-extb’ value to the ‘font-family’ property in the ‘template.css’ file, but then only the Japanese characters were displayed and all other text was lost, and I presume that’s not what you wanted.
A solution that may work, but I haven’t tested, would be: to create a custom field for the text in Japanese, and then modify a copy of the pdf template to display the custom field using the Japanese font as explained here. The
Another alternative is to process the pdf with a software that embeds the fonts. For instance, you could use the ‘pdftocairo’ tool of the Poppler library (Windows version here) as in,
> pdftocairo -pdf 2018-09-02_Invoice_14.pdf test.pdf
I have tested the tool on GNU/Linux and all fonts where embedded in the new pdf file, which surprisingly was smaller (22K) than the original file (49K) in spite of containing all used fonts,
$ pdffonts test.pdf
name type encoding emb sub uni object ID
------------------------------------ ----------------- ---------------- --- --- --- ---------
ZLSITS+DejaVuSansCondensed-Bold TrueType WinAnsi yes yes yes 5 0
VYUNIJ+DejaVuSansCondensed TrueType WinAnsi yes yes yes 6 0
NRPACB+XBRiyaz CID TrueType Identity-H yes yes yes 7 0
GKCFTT+XBRiyaz TrueType WinAnsi yes yes yes 8 0
SOYXSZ+DroidSansFallback CID TrueType Identity-H yes yes yes 9 0