[PyQt] PYQt defaults to fonts looking bold on macOS but C++ Qt does not

Barry Scott barry at barrys-emacs.org
Tue Jul 26 13:10:36 BST 2016

> On 6 Jul 2016, at 11:50, Phil Thompson <phil at riverbankcomputing.com> wrote:
> On 6 Jul 2016, at 11:26 am, Barry Scott <barry at barrys-emacs.org> wrote:
>> Compare the windows snapshots taken for a PyQt5 app and a C++ Qt5 app
>> that use a QLabel control.
>> http://www.barrys-emacs.org/export/Qt5.png
>> http://www.barrys-emacs.org/export/PyQt5.png
>> You can see that the text in PyQt5 looks like it is bold compared to the
>> Qt5 version.
>> On Fedora I see that same text for Qt5 and PyQT5.
>> Please fix this problem in PyQt5.
>> The source code I used is in:
>> http://barrys-emacs.org/export/font-example.tar.gz
>> Note: This bug affects all text, list, tables, line edit everything.
> ...on your system. It works fine for me. PyQt does nothing with fonts.


I know what macOS preference changes this behaviour.

In "System Preferences…”, “General” there is a property,
“Use LCD font smoothing when available” (bottom of the dialog).
If this is ticked PyQt5 text is bold in appearance.
When it is not ticked it looks normal.

But this setting does not change the output of a Qt5 C++ app.

Can you reproduce this problem now?


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