opaque background behind data labels on a line chart

Hello, Michael,
 
Thank you for your question.
 
The chart data labels are currently created using the svg <text> element that doesn't support the background property.
 

1. A possible workaround could be to use the afterchartdraw event to detect the overlapping labels and update the overlapping label's coordinates.

   We have a JSFiddle example demonstrating the described approach: https://jsfiddle.net/flexmonster/52tudxrb/.

   For more details about the afterchartdraw event, please see the following guide.

2. Also, if you hover over a chart element, a tooltip is displayed showing data labels for the involved measures.

   For some cases, a possible solution is to hide the chart data labels and use the tooltips to view details. The chart data labels can be hidden by setting the showDataLabels chart option to false. It is also possible to enlarge the chart nodes making it easier to hover on a particular chart node (see example).

3. In addition, providing more space for the chart by increasing Flexmonster's height could help prevent chart labels from overlapping.

Please let us know if this helps.
 
Kind regards,
Vera