I've seen a product which is effectively a clear (see through) label that you can affix to a CD or DVD to protect the upper (label) surface.
Hunting around the web I've found them in the USA - but it seems the hole in the centre is the large size (40 mm).
I'm looking for some to attach to the inkjet printable DVDs which have a smaller centre piece of 22 mm.
Anyone know where these can be purchased from?