The Custom Certificate plugin provides a rich canvas for customizable certificates you can make for your students. After the completion of a course, the student can access his certificate and download it.
The plugin provides a versatile options page to customize the size and content of the certificate. See a full list of variables here.
The plugin associates a unique code to each certificate and user, to verify its authenticity. Permissions can also be set for the download, printing and sharing of the certificates.
Moodle HQ’s Mark Nelson is the mind behind Custom Certificate plugin. A Particularly Helpful Moodler badge earner for the past four years, Nelson is a frequent speaker at MoodleMoots around the globe and an active contributor both to the core and the plugins of Moodle.
See the plugin version page for installation instructions. It features a guide to customize the fonts of the certificate.
Read the documentation on the plugin here (in development at the time of this writing).