By putting labels on a DVD-R will have any effect playing the movie. I am speaking about the round labels with a photo or some kind of art work.
What has been said here is that most have had disasters with labels on DVD's,they sometimes lift off and destroy your player,So I would suggest not using them. They are more problems then they are worth.
most posts about this ive read say using printable dvd's and a printer that prints disks works fine. i tried labels, makes them unreadable till you remove the label.