When you apply a border to a paragraph in Word 2016 — top, bottom, left, right, or all sides — that format sticks to the paragraph. It's echoed in subsequent paragraphs you type, just like any other paragraph-level format. To apply a border to any or all sides of a paragraph, follow these steps:
Place the insertion pointer in a paragraph.
Click the Home tab.
In the Paragraphs group, click the triangle next to the Borders command button.
The Borders menu appears.
Choose a border style from the menu.
For example, to place a line atop the paragraph, choose Top Border. Its icon is shown here.
The border is applied using the line style, thickness, and color set in the Borders and Shading dialog box.
To apply multiple lines, choose both border styles sequentially. For example, to add rules to a paragraph (a line above and below), first choose the Top Border command, and then click the Borders command again and choose Bottom Border.
Horizontal borders stretch between the paragraph's left and right margins. These margins are different from the page margins.
A common use of paragraph borders is to set off a document title or heading.
When multiple paragraphs are selected, the border is applied to all paragraphs as a group. Therefore, a top or bottom border appears on only the first or last paragraph in the selected block.
If you press Enter to end the paragraph, the border formatting is applied to the following paragraph. For top and bottom borders, the effect is that only the first or last paragraph displays the border line.