Substitution for font unavailable

[lonk]

I have an old Calc template file with fixed font, namely Droid Sans.
When I opened this file in:
Linux Mint 20.2 Cinnamon DE
Version: 7.2.2.2 / LibreOffice Community
Build ID: 20(Build:2)
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Ubuntu package version: 1:7.2.2~rc2-0ubuntu0.20.04.1~lo1
Calc: threaded
The result is:

How does LibreOffice Calc choose a font name to substitute the unavailable font?

[robleyd]

According to the Help, LO uses

the default substitution font that your operating system uses when it encounters an unavailable font in a document.

You can use Tools - Options - LibreOffice - Fonts to override this behaviour.