You may also print invitations and mail them to guests:
Click on the event you wish to invite guests to
Click the 'Forms' tab
If you have enabled Email Invitations, click the Invitation Emails form
Click 'View printable invitation'
Once you click on the View Printable Invitation button, another browser window will open up that contains your invitation
Print from your browser. Watch the margins (should be ¼ inch)