There are several different ways you can add lines
to a form or remove them.
You can add or remove all lines (borders) on all forms of a certain type (for example, all invoices) in Printer Setup.
You can add or remove all lines from an individual form when you print the form.
You can add a line or border to a particular field on a particular form by customizing the form.
If you print sales orders on your company letterhead, you'll probably want to set the Printer Setup setting to have lines on all of your printed sales orders.
If you usually print invoices on Intuit preprinted forms (which already have lines), you'll probably remove all of the lines on printed invoices. This is also done in Printer Setup.
If you occasionally print your invoices on plain paper, however, you can remove all of the lines when you print that form.
If you want to highlight the Total on a particular estimate form, you can add a border around the Total field when you customize that form.
Adding or removing all lines on forms (printer setup)
Adding or removing individual lines on a customized form