By default, the greyed-out gridlines in Excel are not printed. What many people do, to “show” these gridlines on a printed spreadsheet, is to add cell borders. However, there is a simpler and more effective way of printing gridlines.
Go to the Page Layout Ribbon and in the Sheet Options group check the Gridlines Print option. This option can also be accessed using Print Titles under the Page Setup group.
Over and above being simpler to implement, Printed Gridlines are a lot finer and subsequently more subtle then cell borders. As a result, the data is easier to read with the Printed Gridlines still sufficient to enable one to track a line item.