As Confluence Admin you have a few options to make Confluence Export PDF more efficient and customized to your needs.

On the main left panel in “General Configuration” view you can find “PDF EXPORT” section

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Confluence General Configuration Left Panel

PRE-DEFINED EXPORT CONFIGURATIONS

You can Add, Edit, and Delete Export to PDF configurations (Schemas) with names to be used by users.

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Predefined COnfigurations (Schemas)

In the “Generate PDF Schema” view you have several options to customize the final PDF file.

CUSTOM FONTS

You can add Font-Families that be used to Export to PFD. You have two options to add Font:

1. Add a single font file

2. Add a few font-family files

You can find many free fonts here:
https://www.google.com/search?q=free+fonts