Excel offers many border styles that you can apply to separate cells or a selection of cells (Figure 38).
Use the Formatting Palette or the Format Cells dialog to add and format borders.
Select the cell(s) to which you want to add borders.
Choose the type of border you want to apply from the Border Type pop-up menu in the Borders and Shading area of the Formatting Palette (Figure 39).
Figure 39. The Border Type pop-up menu on the Formatting Palette.
To change the style of the border, choose a style from ...