Please see this thread: https://ko.infragistics.com/community/forums/f/ultimate-ui-for-windows-forms/125366/inconsistent-line-widths

I would like an option to disable the anti-aliasing on charts, as it makes lines appear inconsistent in weight, and rounding the line to the nearest whole value would look better in my opinion.

I also think your anti-aliasing is over-weighted, resulting in anti-aliased lines appearing thicker than non-anti-aliased lines.  However, I consider this a bug.