In Rhino Options ->View -> Display Mode -> Wire frame, curves and lines, there is a custom option to change the thickness value. But the values are in pixels integer. So is not possible to make the thick of a line 0,5 1,8 or 1.3 thick. And is useful with anti aliasing to make the lines thinner especially when there is a lot of model information in my screen. I wish for better visual aesthetic workflow Rhino option feature changing the int into decimals doble or floats. Thx for the grate product.
Perhaps it is possible to obtain better results by changing your anti-alias settings. Which GPU do you have and what are the settings - both in Rhino and in the GPU UI?
With 4k will be better but is a feature I wish since since Rhino 1. I jump different GPU and monitors. Jump since rhino start different PC configurations. Actually using W10 64, Ati 7970, 1920x1200, GPU UI settings AA and else driven by software, Rhino setup AAx8
In more detail:
Antialiasing in Rhino on a ATI Radeon is a know problem. ATI apparently doesn’t want to update their drivers for these cards to support OpenGL calls correctly. The ATI FirePro is geared towards OpenGL but also has problems with antialiasing.
Further reading (one among many such posts):
http://discourse.mcneel.com/t/please-help-choosing-video-card-for-rhino-3d-v5/26862