Line Width for rectangle stimuli not working

Adjusting the Line Width values to above ~10 pixels doesn’t make the borders of rectangles any thicker. The Units is set to “pix”. The Monitor Center values are set to the default. The Full-screen window checkbox is checked. Any solutions?

OS (e.g. Win10): MacOs 10.14.6
Computer: MacBookPro, 2018
PsychoPy version (e.g. 1.84.x): 3.2.4
Standard Standalone? (y/n) y

Hi @Leonine, it may be that line widths greater than 10px are not supported on your system:

https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glLineWidth.xhtml