how do I print a packing slip?

[noopy]

I would like to enclose a packing slip. How do I get one so I can print it and include it with the package?

[shipscript]

I use a desktop computer, and a packing slip option is usually visible to me on the label printing page or on the orders page.  I typically print a packing slip prior to printing a postage label, but the option is also available after printing postage.