encasement
Didn't panasonic/matsushita already do this or tried some kind of caddy system (still got my 1x panasonic cdrom in the loft somewhere), I'm pretty sure you can buy DVD-RAM discs in caddies too. I reckon its all down to cost cutting, I mean 1 DVD-R disc costs about 12p how much more would it cost if it was incased in a caddy, I'm guessing by atleast 8x, but the difference wouldn't be so much with a 50Gb blueray recordable media probably not even a 20th of the cost of the disc.