Bugzilla

(In reply to Bob Schultz from comment #2)
> Yes and no. There seems to be a scaling quirk with the nvidia card driving a 4K display. Setting layout.css.devPixelsPerPx to 1.1, and setting the view/density control to compact results in an ok display, sized similarly to the previous version.

Please try the following and report on results. Youe imput is important.

Setting layout.css.devPixelsPerPx to 1.1 will cause a zoom effect and unbalance all other font settings.

The default is a negative -1.0
Please access config editor and reset this back to default as it will be impossible to get all the other settings working as expected.

Then do the following:
via 'Menu bar' toolbar - View > Font Size
Select 'Reset Font Size' first to get back to default
Then select 'increase font size'  or 'decrease font size' as required. 

alternative via Menu app icon:
Menu icon > Font Size > 12px is the default - click on whatever you see as the number icon and it will reset to default 12px
Use the  - and + icons to decrease/increase the font size in the UI.

What font size px  is the most suitable?
The areas I'm most interested in is the 'Folder Pane, Menus and Message List'  because the Message Pane can be otherwise controlled via different method.

(In reply to Bob Schultz from comment #2)
> Yes and no. There seems to be a scaling quirk with the nvidia card driving a 4K display. Setting layout.css.devPixelsPerPx to 1.1, and setting the view/density control to compact results in an ok display, sized similarly to the previous version.

Please try the following and report on results. Your input is important.

Setting layout.css.devPixelsPerPx to 1.1 will cause a zoom effect and unbalance all other font settings.

The default is a negative -1.0
Please access config editor and reset this back to default as it will be impossible to get all the other settings working as expected.

Then do the following:
via 'Menu bar' toolbar - View > Font Size
Select 'Reset Font Size' first to get back to default
Then select 'increase font size'  or 'decrease font size' as required. 

alternative via Menu app icon:
Menu icon > Font Size > 12px is the default - click on whatever you see as the number icon and it will reset to default 12px
Use the  - and + icons to decrease/increase the font size in the UI.

What font size px  is the most suitable?
The areas I'm most interested in is the 'Folder Pane, Menus and Message List'  because the Message Pane can be otherwise controlled via different method.