How do I set up lines indicating where to fold a page as a letter?

[Sebastian]

Where I used to work we printed letters that automatically added very short
lines on the side of the page which indicated three folds for a perfect fit
in a normal envelope. I want to do the same at my new job, but I don't know
how. Please help.

 

[Karin]

Setup a template. Turn View, Ruler on. In the template, use the drawing
tool to draw a short line at the very edge of the page. About 3.5" down and
7.25" down should work. For me the line has to be a certain length in order
to print (.33"). Format the line to whatever thickness you want.

Use the template when you create letters.