If you are shipping your DVDs through the mail, be careful to select a
hub lock style that holds the DVD securely. The photo below shows two
types of hub lock. On the left, the "one catch" type is easy to engage, but
unfortunately also easy to disengage just by bending or shaking the
case.
DVD hub with one catch - not secure
DVD hub with two catches - more secure
In the mail, the disc may come off the hub just due to normal package
handling, and the DVD will subsequently bounce around inside the case
and the underside will be scratched by the hub, as the photo below
indicates (this was a DVD in a case with the "one catch" hub, that was
mailed from CA to NY, then back due to invalid mailing address).
This DVD actually played OK on my player, but it may not
play on every player, and it certainly looks beat up. Unfortunately,
vendors often do not specify the type of hub used on their DVD cases,
or show a photo clear enough to determine it for yourself without
buying a sample. The 3-catch hubs used by Polyline DVD cases reputedly work well.
