The borders for tables that you create within PowerPoint are thin lines by default. You can change the weight of these borders to make them thicker — but even before you do so, there are certain prerequisites to take care of. First of all, if you have applied any of the Table Styles, then some borders may have been set to be invisible. So, you need to set them to be visible first since there’s no sense in thickening an invisible border. Once table borders are visible, you can make changes to their appearance — you can change their color, line style, or thickness.
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