Set up templates for printed letters. A typical example is a welcome letter to print and post to the donor. Generate pdfs for an individual or a group of contacts.
A good welcome pack could include:
This video shows a welcome letter example. You can mail merge in name and address. Print out and include with the other items for posting.
If you are rather needing to print a letter for a group of contacts, you would use the Bulk Letters feature. This feature allows you include merge fields and produce a multi-page PDF file.
More on templates: