Looks like it might be a feature of newer versions of the Plasma 
Desktop.  I'm running Kubuntu 20.04 on the version that I saw the setting.
Most likely you can still hand edit the config file on older versions 
though.

Brian Cluff

On 7/19/20 2:14 PM, Jim via PLUG-discuss wrote:
> I opened system settings, clicked startup and shutdown.  The first 
> option on the top left is Login Screen (SDDM).  I click that and the 
> advanced tab shows.  I click it, but there's no settings 
> synchronization button.  I have Plasma 5.12.9.    You can see what I 
> do have under the advanced tab here https://ibb.co/3snzX6Y
>
> On 7/19/20 10:51 AM, Brian Cluff via PLUG-discuss wrote:
>> I was just poking around the SDDM theme settings and under the 
>> advanced tab I just noticed there is a settings synchronization 
>> button that will allow you to synchronize your desktop settings to 
>> the SDDM theme.  That would probably be the best way to go, and if 
>> that works ignore my last message :)
>>
>> Brian Cluff
>>
>> On 7/19/20 10:46 AM, Brian Cluff via PLUG-discuss wrote:
>>> If you are talking about the font sizes on the login screen itself; 
>>> those font sizes aren't set by the font settings in your desktop 
>>> settings.  The login screen is shared between all users of the 
>>> machine so it has to have it's own settings.
>>> You'll either need to tweak the SDDM theme, or change the resolution 
>>> of the whole system.
>>>
>>> If you are using the breeze sddm theme you can edit it's config file 
>>> at /usr/share/sddm/themes/breeze/theme.conf and there is a font size 
>>> setting in there.
>>>
>>> If you want to make sure that your changes don't get overwritten the 
>>> next time the system updates the theme you might want to do this:
>>>
>>> sudo dpkg-divert --add /usr/share/sddm/themes/breeze/theme.conf
>>>
>>> The above line will cause any future installs of the package to 
>>> write the package's version of the config file to 
>>> /usr/share/sddm/themes/breeze/theme.conf.distrib instead of it's 
>>> normal name.  That way the system will always get your version of 
>>> the config file.
>>>
>>> Brian Cluff
>>>
>>> On 7/19/20 10:13 AM, Jim via PLUG-discuss wrote:
>>>> Good morning,
>>>>
>>>> I've got a machine running Kubuntu 18.04 64 bit.  When I log out 
>>>> and log in or press ctrl alt backspace; beginning at the login 
>>>> screen the text is much smaller.  The first time this happened, I 
>>>> reset the text to make everything the size I wanted.  When I 
>>>> rebooted the machine, the text was too big, so I made it smaller. 
>>>> It wasn't doing this when I first installed the OS on this 
>>>> dinosaur.  Any idea what happened, or more importantly, how I fix it?
>>>>
>>>>
>>>> I went into system settings/fonts.  The sizes for the various fonts 
>>>> are from top to bottom 12 14 14 14 14 12. When I log in a second 
>>>> time without rebooting, the text is much smaller as I described, 
>>>> but these font size settings are the same.
>>>>
>>>>
>>>> thanks
>>>>
>>>>
>>>> ---------------------------------------------------
>>>> PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org
>>>> To subscribe, unsubscribe, or to change your mail settings:
>>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>>
>>> ---------------------------------------------------
>>> PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org
>>> To subscribe, unsubscribe, or to change your mail settings:
>>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>> ---------------------------------------------------
>> PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org
>> To subscribe, unsubscribe, or to change your mail settings:
>> https://lists.phxlinux.org/mailman/listinfo/plug-discuss
> ---------------------------------------------------
> PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org
> To subscribe, unsubscribe, or to change your mail settings:
> https://lists.phxlinux.org/mailman/listinfo/plug-discuss

---------------------------------------------------
PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org
To subscribe, unsubscribe, or to change your mail settings:
https://lists.phxlinux.org/mailman/listinfo/plug-discuss