Majidimehr noted that Blu-ray discs are more like 'open-face sandwiches' and he said that because the bits are close to the surface 'scratching can become a big problem.' He continued, 'So when Sony and others first introduced Blu-ray in Japan they put it in a cartridge to protect it, and of course nobody wants a cartridge around their discs... so then they went through a long process of trying to figure out how to protect that layer and they've come up with different surface material to try and provide that protection, but as you try to coat the disc with a protective layer you also contaminate it so that reduces yields and the number of good discs you can get out of a production run.'
I read somewhere (I wish I had posted this - or maybe I did!) a list of formats that Sony has tried to introduce - and every single one was a failure in the marketplace.
That doesn't bode well for Blu-Ray.