Numbers
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Add a border and background to a chart in Numbers on iPad
You can add a border and a background color to any 2D bar, column, area, or scatter chart.
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Tap the chart, then tap
.
Tap Style, then do any of the following:
Add a background: Tap General, tap Background, then tap Preset, Color, Gradient, or Image and use the controls to adjust the look of the background.
Add a border: Tap Gridlines, then turn on Chart Border.
Note: These options vary depending on the type of chart and data.
You can also add a border around your sheet. To learn more, see Add a border around a sheet.