Highcharts pie chart issue (gaps between pie slices)

Question

I have a half-donut pie chart using a 100-point series in Highcharts. Please see screenshot.

I've spent the last four or five hours trying to figure out why there's a line between each pie slice. It's not a border, because if I change the background color behind the chart to black, I can actually see the black between each pie piece. So there's a 1-pixel gap between each pie piece. I would like the chart just to be a solid color, not have a 1-pixel gap between each pie piece. Pulling my hair out trying to figure out where this setting is. Any help much appreciated.

Answer 1

I was finally able to fix the issue by reading about series.borderWidth. (Thanks to @BarbaraLaird.) This is from the Highcharts API docs:

borderWidth: Number The width of the border surrounding each slice.

When setting the border width to 0, there may be small gaps between the slices due to SVG antialiasing artefacts. To work around this, keep the border width at 0.5 or 1, but set the borderColor to null instead.

Defaults to 1.

I was able to fix the issue by setting borderWidth to 1 and setting borderColor to null. (My borderWidth was previously set to 0 and borderColor was undefined.) That filled in the "gaps" between the antialised slices.