I'll teach you how to show gridlines for Excel when you print your files.
This is a neat little feature that will allow you to have a printed version of your Excel file that looks more like what you will see on your computer without having to manually create borders.
Here is our sample worksheet:
When we go to print preview it will look like this:
You can see on the right side of the image that there are no gridlines or borders of any sort.
Final result as viewed in the print preview:
And here is a screenshot of the full page:
This is a simple thing to do and, depending on your data set, it can help with the readability of the document.
Note that the gridlines only appear where you have data; Excel won't print an entire page in grid format by default if there is not data to show with it.