When exporting to PDF/a-2b, only the used subset of characters is exported.
(For efficiency purposes, this normally makes sense)
When you sign the pdf thereafter, your name may contain characters not yet present in the subset and thus the signature will not properly display.
How can I tell the export function to include the full font and not just the currently used characters ?
Have you already looked in the File>Properties... menu?
And then in the dialog the tab “Font”?
I have not tested it myself, but you can try.
When the original is a scan and has not fonts, the File>Prop… has unfortunately no effect
The PDF standard supports 14 default fonts: Times (4 types), Helvetica (4 types), Courier (4 types), Symbol and ZapfDingbats. If you use these, or OS equivalent, you won’t need to embed fonts.
I tried embedding all fonts in a Writer document and exporting it as Hybrid pdf or as PDF/A-3b, either way only a subset were embedded. I think it might be part of pdf specification.
There are no fonts in a scan, only an image (dots) so cannot embed
In Scribus there is the option to include fonts and a seperarate option to embedd only used characters, so I assume both is possible.
I confess I never checked the result.
@Wanderer You are absolutely right, I checked on Fonts in PDF files | How to embed or subset a font in a PDF