Answers: Manufacturers? They do it during the trade process by glueing or spraying (or by any other chemical procedure) the top lode ;)
Small manufacturer near no machines? They print it on a printable cover
http://shootyourfilm.com/dvd.html
Home manufacturer used to put on stickers, but that's not moral for the go together or they do the printing, too
http://www.supermediastore.com/dvdr-inkp...
Cool home manufacturer don't bother next to adjectives the printing business, they turn the dvd upside down and LightScribe it
http://www.supermediastore.com/lightscri...
They design the contents near softwares call as "CD/DVD Labeling Software" close to "Nero Cover Designer " and afterwards print near disc sticky label printer and pulp resting on the medium.