# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# xAxis.plotBands.zIndex

The z index of the plot band within the chart, relative to other elements. Using the same z index as another element may give unpredictable results, as the last rendered element will be on top. Values from 0 to 20 make sense.